Deoxyribonucleic acid DNA

Timing of Experience

http://epaa.asu.edu/ojs/

Esther Barros Garcia

Human Biology 130 & 132

I Do Really Need To Know My Genes

THE GENETIC TESTING KNOWN AS (DNA) DEOXYRIBONUCLEIC ACID

 For many people, genetic testing may sound like something that is out of a science fiction movie or may sound like it is something that could only be used in the future, but genetic testing is very real and is technology that is available today to the general public. Genetic testing is the process of studying a person’s DNA in order to determine if that person is at risk for a certain health condition or health disorder. This form of testing can have many benefits for people and can be great for the public health in lots of ways, however, at the same time genetic testing can be hurtful to many people and can create unneeded worry and suffering as well.

The benefits of testing someone’s (DNA) Deoxyribonucleic acid can be great; testing can confirm if a person has a medical disorder and then that person can receive early treatment for the illness. Also, if someone is not showing any symptoms of illness now that person might still be sick or have a higher risk of developing an health condition in the future; genetic testing can help them get medical assistance faster and can save their life. Additionally, a (DNA) Deoxyribonucleic acid test can also show negative results and can rule out the chance that someone has inherited an illness or health disorder from their family and can save that person time and worry from misdiagnosis and taking the wrong treatment. It is important for a person to have the best information possible. DNA testing is the best way to understand a person’s health and figure out what illness that person might have because DNA has ALL information about a person; it is a person’s “blueprint” of who they are and what they are made of. (DNA) Deoxyribonucleic acid testing is the only way to really understand everything about a person so it is a necessary and is useful tool in the medical field. If people are aware of all possible illnesses that can be inherited then they can completely protect themselves and take care of their health. One the other hand, there are many other tests that can also detect illnesses such as cancer or diabetes that do not require (DNA) Deoxyribonucleic acid testing, but (DNA) Deoxyribonucleic acid testing is still superior because it can find all health related issues.

Genetic testing can also be very helpful for people who will be future parents thinking about having babies. Testing can inform the couple if they have any inherited gene mutations and if these mutations could possibly give the babies health problems when they are passed down from the parents. This part of DNA testing is very important because understanding recessive genes is important to understanding all health risks that are present but are not expressed. Some diseases and health conditions may skip generations so if someone is a carrier of a recessive mutated gene it is possible that that person’s child may inherit and express the gene. In this case, blood tests could possibly help with finding illnesses, but a (DNA) Deoxyribonucleic acid test is the only way to know for sure if a parent has passed along a mutated gene to their baby. Fetus DNA testing can determine whether or not a baby will be born with physical or mental defects and is the only way to know early enough before the fetus is fully developed. With this information the parents of the child can make the decision to terminate the pregnancy. The issue of terminating a pregnancy has many social and legal complications but the fact is that from a medical point of view it genetic testing allows for options. In the past before this kind of testing was available to the public many parents did not know about a child’s health problems until it was too late and both the child and the parents had no choice but to live and adapt to these physical and mental health conditions. Now thanks to gene testing parents can know early to prepare themselves for a more difficult lifestyle or terminate.

For gene testing to be allowed and all people allowed to have access to the technology a basic concern will still to be discussed; who will have complete access to a person’s DNA information? Should everyday people have access to their own information? Should it be only the doctors? Should it be the companies that conduct and control the testing? Or should it be the insurance companies that pay for the procedures? It is important for someone to receive the best help that they can so I would want medical doctors to have complete access to DNA information to discuss with patients, and everyone should be allowed access to their own personal information at any time. However, if the insurance companies start to have access to people’s DNA information it can lead to an invasion of privacy. This lack of privacy can be very bad because insurance companies like to share information and it is possible that some insurance companies will not cover patients because being born with a genetic health condition is “pre-existing” (Concepts and Current Issues, 6e Johnson)  and that patient can have trouble finding a health insurance company to cover them all because of a lack of privacy issue.

It is important for the right people to have access to DNA information but not if they are going to use it against the patients. If insurance companies get a hold of the data it can lead down the wrong path. Lack of privacy can soon lead to employer’s discrimination against employees or possible future employees. Some employers will not hire people if they have access to a person’s DNA and they see that they have the possibility of developing a health condition. This sort of discrimination is bad because the employee might be qualified and in a healthy condition today, and they might not ever develop their genetic health condition but because they still carry a mutation they might still not receive the job. If privacy is not controlled this sort of discrimination could also spread to everyday people having information about other’s DNA which will lead to further social discrimination. This can then even spread to banking institutions not wanting to give loans to patients and many other forms of discrimination that could affect people in ways they did not consider.

Lack of privacy can also lead to discrimination within the people who have had their DNA tested. In many cases it is known that certain ethnic groups are carriers for specific gene mutations. An example of an ethnic group with a gene mutation is the people of African descent; these people are known to be at higher risk to develop a condition known as sickle cell. This condition is when people have misshaped blood cells that make it hard for blood to travel through the body, and blood flow is blocked which causes organ damages. So does this mean that all people of African descent should be required to take testing for sickle cell? This is another form of discrimination but it is in the public interest so it is complicated. If I was part of an ethnic group that was likely to develop a genetic health condition I would want to be tested and figure out my options sooner rather than later but I wouldn’t want anyone else besides my doctors to know about my condition.

As of 2009, the US government passed a law (GINA) that makes it illegal for employers to use genetic information against their employees. This is great because that means people that who are already hired do not have to worry about losing their jobs if they develop a condition one day. And it also means that people who are searching for jobs only need to worry about their work skills, they do not need to worry about their health being a reason for not getting hired. This new law is a great step forward in terms of discrimination, but it does address the issue of privacy. The law does not make it illegal for insurance companies to share information. So, further action needs to be taken by our government in order to make sure that the privacy issue is looked into.

Now a big concern for many people in the medical field is that people who develop genetic disorders may not be able to deal with the situation. If I  might be  carrying  unpreventable condition, I would want to know on time. So that if the anything could be prevent and I could be cured or adjust to have a better life and enjoy my family that would be great, don’t you think.  I agree with that in order to get something of any kind you need to know how it works, therefore, genetic should   advice counseling, in fact it should be required for people who are allowed to purchase a genetic test? what about counseling afterward is anything negative is found? (found a health condition)Since genes cannot be changed, is nothing a person can do about an inherited condition. The only thing that a patient can do is try to receive early treatment to control the disease. Many people can become depressed to find out they have an uncontrollable disease and can lead to all around bad mental health or even worse some people might decide to commit suicide because they cannot deal with the reality of having a serious health condition.  

By Concepts and Current Issues, 6e Johnson   

Developmental psychology focuses on the development of individuals across their lifespan within the context of family, peer groups, child-care and after-school programs, schools, neighborhoods, and larger communities and society. It considers the well-being of children, youth, and adults, vis--vis the cognitive, emotional, social, academic, and health domains. Developmental research often focuses on disparities among groups (for example, gender, resources such as parental income and education, ethnicity, and immigrant status) as well as the ways in which equity among groups may be promoted.Learning Goals & Objectives Upon completion of this course, students should have accomplished the following goals an understanding of the research methods used by developmental psychologists.  An appreciation for major developmental changes occurring from birth to adolescence. Knowledge of various types of atypical development in childhood.  Assessment Criteria What is Developmental Psychology? :Knowledge of various types of atypical development in childhood. Assessment Criteria  What is Developmental Psychology?

Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrates, nucleic acids compose the three major macromolecules essential for all known forms of life. Most DNA molecules are double-stranded helices, consisting of two long biopolymers made of simpler units called nucleotides—each nucleotide is composed of a nucleobase (guanine, adenine, thymine, and cytosine), recorded using the letters G, A, T, and C, as well as a backbone made of alternating sugars (deoxyribose) and phosphate groups (related to phosphoric acid), with the nucleobases (G, A, T, C) attached to the sugars.

Elements–Atoms–Molecules and Compounds•Chemical Reactions–Ionic, Covalent, and Hydrogen Bonding•Properties of Water•Acids and Bases and Buffers•Molecules of Life–Carbohydrates, Lipids, Proteins, Nucleic acids, ATP•Basic Chemistry•There are 92 naturally-occurring elements.–Over 90% of human body is composed of four 

elements.Carbon.Nitrogen.Oxygen.Hydrogen.•Atoms•An atom is the smallest unit of matter that retains an element’s physical and chemical properties.–Positively-charged protons and neutral neutrons are located in the nucleus.–Negatively-charged electrons orbit the nucleus in shells.•Molecules and Compounds•A molecule is a group of atoms bonded together.•A compound is a group of molecules bonded together.•Ionic Reactions•During an ionic reaction, atoms give up or take on an electron to stabilize their outer shells.•Ions are particles that carry a positive (+) or negative (-) charge.–The attraction between oppositely charged sodium ions and chloride ions forms an ionic bond.•Ionic Reaction•Covalent Reactions•In covalent reactions, atoms share electrons in covalent bonds instead of losing or gaining them.–A single bond is formed when atoms share a single pair of electrons.–A double bond is formed when atoms share two pairs of electrons.–A triple bond is formed when atoms share three pairs of electrons.•Covalent Reactions•Hydrogen Bonding•A hydrogen bond occurs when a covalently bonded hydrogen is positive and is attracted to a negatively charged atom.•Example: H2O, water.–Electrons in water - more time circling larger oxygen atom than smaller hydrogen atom.•Models of Water Molecules•Hydrogen Bonding between Water Molecules•Properties of Water Critical for Life•Water is liquid at room temperature.•Water is a solvent for polar molecules.•Water molecules are cohesive.•Water temperature rises and falls slowly.•Water has a high heat of vaporization.•Frozen water is less dense than liquid water.•Density of Ice vs. Liquid Water•Acids and Bases•Acids dissociate in water and release hydrogen ions (H+).•Bases take up hydrogen ions (H+) or release hydroxide ions (OH-).–Buffers prevent large changes in amounts of acids and bases in body by taking up excess hydrogen ions or hydroxide ions.•The pH Scale•Molecules of Life•Four categories of molecules are unique to cells.–Carbohydrates.–Lipids.–Proteins.–Nucleic Acids.vATP•Carbohydrates•Carbohydrates function for quick and short-term energy storage.–Monosaccharide (simple sugar).vGlucose.–Disaccharide.vSucrose: Glucose + Fructose•Complex Carbohydrates•Polysaccharides.–Starch (plants).–Glycogen (animals).–Cellulose (plant cell walls).•Lipids•Lipids contain more energy per gram than any other biological molecule.–Do not dissolve in water.vAbsence of polar groups.–Fats.vAnimal origin, solid at room temperature.–Oils.vPlant origin, liquid at room temperature.•Structure of a Fat Molecule•Saturated and Unsaturated Fatty Acids• A fatty acid is a carbon-hydrogen chain ending with -COOH.–Saturated fatty acids contain only single bonds between the carbon atoms.–Unsaturated fatty acids contain one or more double bonds in the carbon chain.–There are two essential fatty acids, linoleic and linolenic fatty acid.•Fatty Acid Stacking•Trans Fats: Unnatural Fatty Acids•How Detergents Work•Phospholipids•Phospholipids contain a phosphate head and fatty acid tails.–Polar head and non-polar tails.vSoluble in water.•Phospholipids•Steroids•Steroids are lipids with a backbone of four fused carbon rings.–Estrogen and testosterone.••Proteins•Proteins are macromolecules with amino acid subunits.–An amino acid has a central carbon atom bonded to a hydrogen and three groups.ØPolypeptide – Single chain of amino acids.–•Proteins•ProteinsvPeptide bond - Any bond joining two amino acids.•Proteins•Amino Acids•Amino Acids•Amino Acids•Amino Acids•Essential Amino Acids•Levels of Protein Organization•Primary Structure.–Linear sequence of amino acids.•Secondary Structure.–Polypeptide takes on orientation in space.•Tertiary Structure.–Final three-dimensional shape.•Quaternary Structure.–Proteins with more than one polypeptide.•Nucleic Acids•Nucleic acids are huge macromolecules composed of nucleotides.–A nucleotide is constructed of a phosphate, a pentose sugar, and a nitrogenous base.–Deoxyribonucleic acid (DNA).vDouble-stranded helix.–Ribonucleic acid (RNA).vSingle stranded.•Structure of a Nucleotide•DNA Structure•(ATP) Adenosine TriphosphateResults (Gel box 9)Chemistry of Life•

Basic ChemistryDNA: Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrate…

E Barros Garcia

Human Biology 130 and   132

I Do Really Need To Know my genesFor many people, genetic testing may sound like something that is out of a science fiction movie or may sound like it is something that could only be used in the future, but genetic testing is very real and is technology that is available today to the general public. Genetic testing is the process of studying a person’s DNA in order to determine if that person is at risk for a certain health condition or health disorder. This form of testing can have many benefits for people and can be great for the public health in many ways, however, at the same time genetic testing can be hurtful to many people and can create unneeded worry and suffering as well.The benefits of testing someone’s DNA can be great; testing can confirm if a person has a medical disorder and then that person can receive early treatment for the illness. Also, if someone is not showing any symptoms of illness now that person might still be sick or have a higher risk of developing an health condition in the future; genetic testing can help them get medical assistance faster and can save their life. Additionally, a (DNA) Deoxyribonucleic acid test can also show negative results and can rule out the chance that someone has inherited an illness or health disorder from their family and can save that person time and worry from misdiagnosis and taking the wrong treatment. It is important for a person to have the best information possible. DNA testing is the best way to understand a person’s health and figure out what illness that person might have because DNA has ALL information about a person; it is a person’s “blueprint” of who they are and what they are made of. (DNA) Deoxyribonucleic acid testing is the only way to really understand everything about a person so it is a necessary and is useful tool in the medical field. If people are aware of all possible illnesses that can be inherited then they can completely protect themselves and take care of their health. One the other hand, there are many other tests that can also detect illnesses such as cancer or diabetes that do not require (DNA) Deoxyribonucleic acid testing, but DNA Deoxyribonucleic acid testing is still superior because it can find all health related issues.Genetic testing can also be very helpful for people who will be future parents thinking about having babies. Testing can inform the couple if they have any inherited gene mutations and if these mutations could possibly give the babies health problems when they are passed down from the parents. This part of DNA testing is very important because understanding recessive genes is important to understanding all health risks that are present but are not expressed. Some diseases and health conditions may skip generations so if someone is a carrier of a recessive mutated gene it is possible that that person’s child may inherit and express the gene. In this case, blood tests could possibly help with finding illnesses, but a DNA test is the only way to know for sure if a parent has passed along a mutated gene to their baby. Fetus DNA testing can determine whether or not a baby will be born with physical or mental defects and is the only way to know early enough before the fetus is fully developed. With this information the parents of the child can make the decision to terminate the pregnancy. The issue of terminating a pregnancy has many social and legal complications but the fact is that from a medical point of view it genetic testing allows for options. In the past before this kind of testing was available to the public many parents did not know about a child’s health problems until it was too late and both the child and the parents had no choice but to live and adapt to these physical and mental health conditions. Now thanks to gene testing parents can know early to prepare themselves for a more difficult lifestyle or terminate.For gene testing to be allowed and all people allowed to have access to the technology a basic concern will still to be discussed; who will have complete access to a person’s DNA information? Should everyday people have access to their own information? Should it be only the doctors? Should it be the companies that conduct and control the testing? Or should it be the insurance companies that pay for the procedures? It is important for someone to receive the best help that they can so I would want medical doctors to have complete access to DNA information to discuss with patients, and everyone should be allowed access to their own personal information at any time. However, if the insurance companies start to have access to people’s DNA information it can lead to an invasion of privacy. This lack of privacy can be very bad because insurance companies like to share information and it is possible that some insurance companies will not cover patients because being born with a genetic health condition is “pre-existing” (Concepts and Current Issues, 6eJohnson)and that patient can have trouble finding a health insurance company to cover them all because of a lack of privacy issue.

It is important for the right people to have access to DNA information but not if they are going to use it against the patients. If insurance companies get a hold of the data it can lead down the wrong path. Lack of privacy can soon lead to employer’s discrimination against employees or possible future employees. Some employers will not hire people if they have access to a person’s DNA and they see that they have the possibility of developing a health condition. This sort of discrimination is bad because the employee might be qualified and in a healthy condition today, and they might not ever develop their genetic health condition but because they still carry a mutation they might still not receive the job. If privacy is not controlled this sort of discrimination could also spread to everyday people having information about other’s DNA which will lead to further social discrimination. This can then even spread to banking institutions not wanting to give loans to patients and many other forms of discrimination that could affect people in ways they did not consider.Lack of privacy can also lead to discrimination within the people who have had their DNA tested. In many cases it is known that certain ethnic groups are carriers for specific gene mutations. An example of an ethnic group with a gene mutation is the people of African descent; these people are known to be at higher risk to develop a condition known as sickle cell. This condition is when people have misshaped blood cells that make it hard for blood to travel through the body, and blood flow is blocked which causes organ damages. So does this mean that all people of African descent should be required to take testing for sickle cell? This is another form of discrimination but it is in the public interest so it is complicated. If I was part of an ethnic group that was likely to develop a genetic health condition I would want to be tested and figure out my options sooner rather than later but I wouldn’t want anyone else besides my doctors to know about my condition.As of 2009, the US government passed a law (GINA) that makes it illegal for employers to use genetic information against their employees. This is great because that means people that who are already hired do not have to worry about losing their jobs if they develop a condition one day. And it also means that people who are searching for jobs only need to worry about their work skills, they do not need to worry about their health being a reason for not getting hired. This new law is a great step forward in terms of discrimination, but it does address the issue of privacy. The law does not make it illegal for insurance companies to share information. So, further action needs to be taken by our government in order to make sure that the privacy issue is looked into.Now a big concern for many people in the medical field is that people who develop genetic disorders may not be able to deal with the situation. If I  might be  carrying  unpreventable condition, I would want to know on time. So that if the anything could be prevent and I could be cured or adjust to have a better life and enjoy my family that would be great, don’t you think.  I agree with that in order to get something of any kind you need to know how it works, therefore, genetic Should  counseling be required for people who are allowed to purchase a genetic test? what about counseling afterward is anything negative is found? (found a health condition)Since genes cannot be changed, there is nothing a person can do about an inherited condition. The only thing that a patient can do is try to receive early treatment to control the disease. Many people can become depressed to find out the they have an uncontrollable disease and can lead to all around bad mental health or even worse some people might decide to commit suicide because they cannot deal with the reality of having a serious health condition.http://wps.aw.com/bc_johnson_humanbio_6/176/45108/11547833.cw/index.html

By Concepts and Current Issues, 6e Johnson Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrates, nucleic acids compose the three major macromolecules essential for all known forms of life. Most DNA molecules are double-stranded helices, consisting of two long biopolymers made of simpler units called nucleotides—each nucleotide is composed of a nucleobase, recorded using the letters G, A, T, and C, as well as a backbone made of alternating sugars and phosphate groups, with the nucleobases attached to the sugars.en.wikipedia.org · Text under CC-BY-SA license Analysis Via PCR & Gel Electrophoresis of Alu Repeats Experiments 16 & 17 BIOL 132, Outline Results of Experiments 16 & 17 doing PCR for Alu repeats from cheek cell DNA and analysis with gel electrophoresis and ethidium bromide The Polymerase Chain Reaction Can be used to rapidly amplify DNA sequences to obtain million of copies DNA to be amplified, primers, heat-stable DNA polymerase are combined Repeated heating and cooling cycles allow for rapid amplification of a sequence of DNA defined by the primers Techniques of Recombinant DNA Technology

Multiplying DNA in vitro: The Polymerase Chain Reaction (PCR) Repetitive process consisting of three steps Denaturation Priming Extension Can be automated using a thermocycler Polymerase chain reaction (PCR) Polymerase chain reaction (PCR) Techniques of Recombinant DNA Technology Separating DNA Molecules: Gel Electrophoresis and the Southern Blot Gel electrophoresis Separates molecules based on electrical charge, size, and shape Allows scientists to isolate DNA of interest Negatively charged DNA drawn toward positive electrode Agarose makes up gel; acts as molecular sieve Smaller fragments migrate faster and farther than larger ones Determine size by comparing distance migrated to standards Gel electrophoresis Techniques of Recombinant DNA Technology Separating DNA Molecules: Gel Electrophoresis and the Southern Blot Southern blot DNA transferred from gel to nitrocellulose membrane Probes used to localize DNA sequence of interest Northern blot – used to detect RNA Uses of Southern blotsGenetic “fingerprinting” Diagnosis of infectious diseaseDemonstrate incidence and prevalence of organisms that cannot be cultured The Southern blot technique Results (Gel box 13) Results (Gel box 16) Results (Gel box 6) Results (Gel box 15)

http://wps.aw.com/bc_johnson_humanbio_6/176/45108/11547833.cw/index.html

•Regulation of blood pressure involves how fast and how hard the left ventricle pumps and the contractile state of the arterioles.–All of this is controlled by the autonomic nervous system and hormones.•Blood Flow in Capillaries and Veins•Slow movement of blood through capillaries allows time for exchange of substances between the blood and surrounding tissues.•Venous return is dependent on three factors.–Skeletal muscle contraction.–Presence of valves in veins.–Respiratory movements.•At any one time, about 70% of the blood is in the vein•The Cardiovascular Pathways•Cardiovascular system includes two circuits.–Pulmonary circuit circulates blood through the lungs.vPulmonary arteries take oxygen-poor blo

od to the lungs, and pulmonary veins return oxygen-rich blood to the heart.–Systemic circuit takes blood from the left ventricle and then back to the right atrium.•Cardiovascular Syste•Lymphatic System•Lymphatic system consists of lymphatic vessels and lymphatic organs.–Three functions contribute to homeostasis.vLymphatic capillaries take up excess tissue fluid, and return it to bloodstream.vLacteals receive lipoproteins (fats) and transport them to bloodstream.vLymphatic system helps defend body against disease.••Lymphatic System•Lymphatic Organs•Lymph nodes filter lymph because macrophages phagocytize debris or pathogens and activate lymphocytes.•Spleen cleanses blood with macrophages.–Filters debris, pathogens, and worn-out red blood cells.•Lymph Node•Homeostasis•Homeostasis is possible only if the cardiovascular system delivers oxygen and nutrients to, and takes metabolic wastes away from, the tissue fluid surrounding cells.–Cardiovascular system must work with other systems to maintain homeostasis.–Lymphatic system aids cardiovascular system by returning tissue fluid to the blood and helps clean the fluid–Nervous and endocrine systems help maintain cardiovascular system.•Need to Know1.Blood Vessels: Understand structure and importancea)Arteries, arteriolesb)Capillariesc)Venules, veins2.Heart: General structurea)Chambers and valves3.Passage of blood through the hearta)Know the route of blood through atria and ventriclesb)“lub-dup” sound; know the valves that cause the sound•Need to Know (Con’t)4.Features of cardiovascular systema)Increasing surface area as get to capillariesb)Decreasing surface area as get back into the veinsc)Regulation of blood pressured)Regulation of venous return5.Cardiovascular pathwaysa)Pulmonary circuitb)Systemic circuit6.Lymphatic system: Understand functions and importancea)Returns tissue fluid to the blood; has valves like veinsb)Macrophage in lymph nodes help clean tissue fluidc)Allow for transport of fats from digestive system to blood•Need to Know (Con’t)7.Functions of the Cardiovascular Systema)Transportation; oxygen, nutrients, wastes, hormones.b)Maintenance of body temperaturec)Defense; carriers defensive cells and proteins to areas of the body under attack

http://www.appi.org/Pages/AcademicPsychiatry.aspxhttp://med.stanford.edu

*Timing of the experience in child development refers to the terms critical period, sensitive period, and windows of opportunity.

http://www.youtube.com/watch?feature=player_embedded&v=OinqFgsIbh0

http://www.youtube.com/watch?v=8hLubgpY2_w

http://www.youtube.com/watch?v=dmMXtZhx7io

https://smccd.mrooms.net/mod/resource/view.php?id=556171

Chapter 2

Protons and neutrons have about equal masses; protons and electrons have

charges; electrons have very little mass.

The one electron of each hydrogen atom completes the orbital of the other.

Polar and charged molecules are capable of forming hydrogen bonds with water,

so they are easily dissociated from each other and easily surrounded by water

molecules.

In covalent bonds, electrons are shared and rotate around both atoms, forming a

strong attraction between the two atoms. Ionic bonds are formed by the

attractive forces between oppositely-charged molecules. Covalent bonds are the

stronger of the two, and hence are harder to break.

Potential energy is energy that is not actively doing anything, but can be stored

or used, as in the energy in glucose or ATP. Kinetic energy is working energy

that is actively facilitating work, as in the energy removed from ATP to help an

endothermic reaction occur.

Saturated fats have all the possible hydrogens attached to carbons; unsaturated

fats are missing some of these hydrogens. Saturated fats tend to be “stiffer”

than unsaturated fats. Saturated fats tend to be solid at room temperature;

unsaturated fats tend to be liquid.

Cholesterol is a component of cell membranes. It’s also required for the synthesis

of the reproductive hormones, estrogen and testosterone.

A protein’s shape is determined by weak chemical bonds (hydrogen bonds and

disulfide bridges) between some of the amino acids that comprise the protein.

The huge variety of protein shapes is a reflection of the nearly infinite number of

possible amino acid sequences in proteins.

All rights reserved.

Enzymes help chemical reactions to occur fast enough for life to proceed.

Without them, reactions do happen, but not fast enough.

ATP functions like a rechargeable battery, temporarily storing energy until it is

used for life’s energy-requiring processes.

Chapter 3

Answers to Concept Review

Diffusion is only is effective over very short distances, so cells must remain small

to be able to supply themselves with nutrients and get rid of wastes.

a. -All living things are composed of cells and cell products.

b. -A single cell is the smallest unit that exhibits all the characteristics of life.

c. -All cells come only from pre-existing cells.

The heads of phospholipids are oriented toward the outside and the inside of the

membrane, the tails toward the center of the membrane. The heads can bond

with water; the tails cannot, but they can link with other tails. “Like seeks like.”

Passive transport always occurs in the direction of an area of high concentration

to an area of lower concentration. Passive transport does not require energy.

Diffusion through the lipid membrane, diffusion through channels, and facilitated

transport are examples of passive transport.

Endocytosis brings materials into a cell in bulk; exocytosis expels material out of

a cell. Molecules transported by endocytosis or exocytosis are often too large to

cross the cell membrane by active transport or diffusion.

The sodium-potassium pump is an active transport mechanism that keeps a

lower concentration of sodium in a cell than is in the environment and a higher

concentration of potassium in the cell than is in the environment. The pump is

constantly working against the diffusion of both types of atoms. The sodiumpotassium

pump is important in maintaining cell volume and also the electrical

charge across the membrane.

In both of these cases, water moves from an area or cell with a higher

concentration of water to an area with a lower concentration of water. A high salt

environment, or a hypertonic environment, causes water to move from the cell

into the solution, resulting in shrinkage of the cell. A low salt environment, or

hypotonic environment, causes water to move into the cell, sometimes causing

the cell to burst, or lyse.

Vesicles are membrane-bound spheres that enclose something within the cell.

Vesicles may be secretory (for exporting materials from the cell), endocytotic (for

importing materials into the cell), or they may contain powerful enzymes or the

waste products of cellular digestion.

The four stages of production of ATP from glucose are: glycolysis, a preparatory

step leading into the citric acid cycle, the citric acid cycle, and the electron

transport system. The last step yields the most ATP.

Oxygen is required to complete the chemical reactions of the electron transport

system. Without oxygen, the system backs up with no energy extracted from the

citric acid cycle and the electron transport chain; only the very limited amount of

ATP from glycolysis is produced.

Chapter 4

Advantages include greater size and the ability to seek or maintain an

environment conducive to life. Disadvantages include the specialization that

occurs in body tissues, limiting a particular cell’s response to change, and the

need for greater resources to grow and survive.

Epithelial tissues cover organs and line vessels; connective tissues are a collection

of tissues such as cartilage, bone, and blood with specialized functions;

muscle tissue contracts, facilitating movement; nervous tissue generates and

transmits electrical impulses throughout the body.

Tight junctions seal the plasma membranes of adjacent cells tightly together so

that nothing can pass between the cells; Adhesion junctions are looser and allow

for some movement between cells to facilitate bending and stretching; Gap

junctions represent connecting channels made of proteins that permit movement

of ions between cells.

An organ is a structure comprised of two or more tissues joined together for a

specific common function; an organ system is comprised of more than one organ

and supportive tissues that serve a broad common function.

Integumentary (protection), skeletal (support), muscular (movement),

circulatory (transport), lymphatic (filtering), respiratory (gas exchange), nervous

(control and coordination), endocrine (hormone production), digestive (provision

of nutrients), urinary (excretion of chemical wastes), reproductive (reproduction).

The fluid between cells.

Thoracic and abdominal cavities.

Negative feedback mechanisms operate in such a way that deviations from the

desired condition are automatically detected and counteracted. In a positive

feedback system, a change in the controlled variable sets in motion a series of

events that amplify the original change.

Homeostasis maintains the internal environment of a cell or of the entire body in

a relatively constant state. Without the ability to maintain homeostasis, cells and

tissues would not be able to operate efficiently and the organism would be

compromised.

The control center receives input from the sensor and compares it to the correct,

internally set value of the controlled variable. When these are not in agreement,

the control center sends signals to an effector.

Chapter 5

Support, movement, protection, formation of blood cells, mineral storage.

Red bone marrow is the site of blood cell production, specifically red blood cells,

neutrophils, and platelets. Yellow bone marrow is a site of fat storage for energy

used by the bone tissue.

During growth, new cartilage is added to the outside surface of the plate (facing

the ends of the bone). At the same time, cartilage on the inside surface of the

plate (facing the center of the bone) is converted to bone. Thus, the bone grows

in length as the growth plates “migrate” outward.

Bones can slowly change shape over many years because how bone is deposited

and resorbed depends on the forces, or stress, applied to the bone.

Compressive stress on bones stimulates osteoblast activity in the areas of

greatest stress, adding bone tissue to that area. Osteoclasts are stimulated to

work on areas of lesser stress, thinning out these areas. The combination reforms

the bone in response to the stress on it, making the bone stronger and more able

to handle the forces placed on it.

Cervical, thoracic, lumbar.

Spinal nerves not yet injured might be injured during a move, causing additional

damage and even paralysis.

Synovial joints are lined with hyaline cartilage that has more “give” to it than

bone and can be repaired more easily. The joints are kept moist by a synovial

membrane that maintains a sac of fluid within the joint to further cut down

friction and prevent rubbing of the cartilage plates.

Flexion decreases the angle of a joint. Extension increases the angle of a joint

Osteoarthritis is an inflammation of a joint due to the degeneration of the joint

over time. The cartilage wears out at a faster rate than it can be replaced.

Rheumatoid arthritis is an inflammation of the joint due to an autoimmune

process. The person’s immune system is attacking the tissues of the joint.

Chapter 6

Answers to Concept Review

Examples of muscles resisting movement are the maintenance of upright posture

and the maintenance of the diameter of blood vessels against the pressure

exerted by blood.

When the origin end of a muscle is kept stationary and the muscle is shortened,

the insertion end of a muscle moves toward the origin, causing a specific body

movement.

Calcium relays the signal from the T tubules, bringing the stimulus to the

contractile proteins. The presence of the calcium on the actin molecule allows the

cross-bridges to form between actin and myosin, causing contraction.

The permanent stiffening of muscles after death is caused by depletion of ATP.

ATP must be present for the myosin head to detach from actin, so in the absence

of ATP the muscle remains in the contracted state.

Insufficient ATP for contraction, and psychological factors such as discomfort or

boredom of repetitive tasks.

Summation is the increase in muscle force caused by increasing the rate of

stimulation of motor units. Repeated nerve stimulation results in more calcium

being present, which results in greater force generation.

Heart rate is controlled at the level of the heart by certain cardiac cells that

function as pacemakers. Although the heart rate is also influenced by nerves, the

heart would still beat on its own even if all the nerves were severed.

A reflex system assists in maintaining tone to skeletal muscles. As long as there

is some stretching of the muscle, signals are sent to the spinal cord and random

motor units are fired within the muscle to maintain tone. Tone in smooth muscle

can be maintained without external activation.

A motor unit consists of a single neuron and all of the muscle cells it innervates.

The fewer the number of muscle cells in a motor unit, the greater the control

because more motor units need to be fired to achieve the contraction desired. If

more muscle cells are attached, the contraction is stronger but fine control is

reduced.

Creatine phosphate stored within the cell; glycogen stored within the cell;

glucose and fatty acids supplied to the cell by the blood during aerobic

metabolism.

Chapter 7

Answers to Concept Review

Transportation of all substances needed anywhere in the body; regulation of

temperature, water volume, and pH; defense against infections and from

excessive blood loss.

Hemoglobin carries oxygen from the lungs to the tissues, delivering it to tissues

when a significant oxygen concentration gradient is present. Hemoglobin also

carries some CO2 back to the lungs, where it is eliminated through respiration.

Certain cells in the kidneys monitor the availability of oxygen. If the oxygen

level drops, the kidney cells release the hormone erythropoietin. Erythropoitin

stimulates the production of red blood cells by the red bone marrow.

Hematocrit is the percentage of whole blood that consists of red blood cells

(RBCs). Hematocrit is important because it is a relative measure of the oxygencarrying

capacity of blood. A low hematocrit signals anemia.

Damaged RBCs become trapped in the liver and spleen and are removed by

phagocytic cells that break down the cell and process the hemoglobin. The iron

is removed and the proteins are broken down, both for recycling within the body.

The bilirubin derived from the heme is secreted into the intestines as part of bile,

and ultimately excreted.

Both neutrophils and eosinophils are phagocytic, but for different things.

Neutrophils primarily attack bacteria and protect the human body from

infection. Eosinophils phagocytize antigen-antibody complexes that are seen in

allergic reactions.

Damage occurs in a blood vessel, which stimulates platelets to form a temporary

plug to stop blood loss through the damaged vessel. At the same time, the

coagulation cascade is initiated, finally forming a fibrin clot at the site of the

damage. The fibrin clot will stay in place long enough for tissue repair to occur.

Blood Type Surface Antigen Plasma Antibody (ies)

A A B

B B A

None A and B

AB A and B None

The immune system can construct antibodies to antigens that we do not have. A

person classified as Rh negative does not have the Rh antigen. If this person is a

pregnant woman and her child is Rh positive, it is possible that she might be

exposed to the baby’s blood and develop immunity against the Rh antigen. If this

occurs, her immune system will attack the RBCs of any subsequent Rh positive

children she carries.

Anemia can be present because of production problems, such as insufficient iron

for hemoglobin synthesis, or inadequate Vitamin B12 for nucleic acid synthesis,

as in pernicious anemia. Anemia may also be present due to an abnormal

hemoglobin, as in Hemoglobin S causing sickle cell anemia. Blood may be lost

from the body due to hemorrhage.

Chapter 8

Answers to Concept Review

The heart is one muscle that cannot afford to experience fatigue! If it did, normal

body functions would be compromised due to decreased blood delivery.

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The walls of arteries and veins are comprised of the same three layers. The

innermost layer (endothelium) is comprised primarily of endothelial cells and

some supporting connective tissue. The middle layer is primarily smooth

muscle, along with some collagen and elastic fibers. The outermost layer is

mostly made of connective tissue. Arteries have a much thicker middle layer,

compared to veins. Capillaries have only one layer (the endothelium).

A blood pressure cuff is applied to the upper part of the arm, and the pressure

meter is placed where it can be easily viewed. A stethoscope is placed on the

inner surface of the elbow. The cuff is inflated and then slowly deflated while

monitoring the stethoscope for tapping or thumping sounds and observing the

pressure meter. The first sound is heard at systolic pressure. When sounds are

no longer heard, that number is recorded as the diastolic pressure.

The heart valves are one-way valves; they close when pressure falls within the

heart chamber directly behind them, preventing backflow of blood.

The pulmonary circuit carries oxygen-poor blood to the lungs and oxygen-rich

blood back to the heart. The systemic system carries oxygen-rich blood to the

tissues of the body and oxygen-poor blood back to the heart.

Atrial and ventricular diastole take 0.4 second, and the ventricles fill with blood

through gravity; the AV valves are open, and the semilunar valves are closed.

Atrial systole takes 0.1 second; both atria contract, filling the ventricles; the

semilunar valves are closed, and the AV valves are open. Ventricular systole

takes 0.3 second; both ventricles contract, the AV valves close, the semilunar

valves open, and blood leaves the heart. The closing of the AV valves causes the

first sound (lub), and the closing of the semilunar valves at the end of ventricular

systole causes the second sound (dub).

The SA node initiates the electrical activity of the heart and sends a wave of

depolarization through the atria. When the electrical activity reaches the AV node

the AVA nodes directs the electrical activity down the interventricular septum to

the ventricles. As a result, the ventricles contract in a coordinated fashion,

forcing blood into the pulmonary trunk and aorta.

The thick walls of the arteries allow pressure to be maintained while sending the

blood around the body; this is not needed in veins. The distensibility of the veins

allows for pooling of the blood. In effect, the veins serve as the volume reservoir

for most of the blood.

Epinephrine.

Don't smoke; watch cholesterol levels; perform regular, moderate exercise;

control blood pressure; maintain a healthy weight; screen for and control

diabetes; avoid chronic stress.

Chapter 9

Answers to Concept Review

Pathogens are organisms that come from outside our bodies and cause damage

to tissues and biological processes. Examples include bacteria, such as

Staphylococcus; viruses, such as HIV; fungi or yeasts, such as Candida albicans;

protozoa, such as the cause of malaria; and prions, such as the cause of Mad

Cow disease.

Viruses cannot reproduce on their own. In order to reproduce they must enter a

living cell and use its organelles to produce new viral DNA and proteins.

All rights reserved.

Prions are misfolded infectious proteins that can cause normal proteins within a

cell to misfold as well. Ultimately this disrupts cell function and may result in cell

death.

The spleen helps remove old red blood cells and invading microorganisms; the

thymus produces the hormones thymosin and thymopoietin, which cause T

lymphocytes to mature; and the tonsils protect the throat by filtering out many

of the microorganisms that are present.

Redness, warmth, swelling, pain.

Nonspecific defenses do not target specific pathogens. Instead, they appear in

response to all sorts of health challenges. Specific defenses (such as immune

responses) recognize and target only specific pathogens.

An antigen is any material that can activate the production of antibodies and

combine with them. All cells and viruses have identifying antigens on the surface

of their membranes. During fetal development, our immune system learns which

antigens are ours (or self) and will not make antibodies against them.

Antibodies are made just against foreign antigens.

Identification of each person’s cellular antigens as “self” occurs during embryonic

development. In adulthood, then, our own immune systems generally ignore cells

identified as “self”.

When cytotoxic T cells locate and bind to a target cell, a protein called perforin

is released and inserted into the plasma membrane of the target cell. This

protein forms large pores or holes in the membrane, allowing water to enter.

The target cell swells and may eventually burst.

Vaccines are usually made from dead or weakened pathogens or from a specific

antigen of that pathogen. When injected into a person, vaccines cause the

person’s immune system to produce antibodies and memory cells against that

antigen. Consequently, when the person is exposed to that specific live

pathogen, his/her immune system is primed to mount a vigorous attack.

Chapter 10

Answers to Concept Review

The nose warms and humidifies the incoming air; filters inhaled air and screens

out foreign particles; is responsible for our sense of smell; serves as a resonating

chamber for a distinctive voice.

The larynx is larger and the vocal cords are longer in men. Men’s voices

therefore have a lower pitch.

Movement of cilia can be inhibited, leading to less clearing of the bronchial tree.

Toxins in smoke also result in increased mucus production.

Bronchioles are smaller, have no cartilage to support the airway, and have less

smooth muscle than bronchi.

Pressure goes down when the container is enlarged and up when the container is

made smaller.

The diaphragm contracts and flattens, expanding the volume of the chest cavity

and causing the lungs to expand. Air comes in to fill the available space. If a

deeper breath is needed, the external intercostals muscles pull the ribs up,

expanding the chest even more—allowing more air to come in. To breathe out,

the diaphragm and the chest muscles relax, causing the weight of the chest to

compress the chest, making the space smaller and forcing air from the lungs.

Partial pressure is the pressure of each individual gas in a mixture of gases.

Diffusion of each gas depends on its partial pressure.

All rights reserved.

Approximately one-eighth of the air in the alveoli is actually exchanged with the

atmosphere with each breath. Oxygen is constantly diffusing from the alveoli into

the blood, decreasing the alveolar oxygen concentration.

In the tissues, the CO2 waste that is formed during metabolism combines with

water to form carbonic acid (H2CO3). The carbonic acid then dissociates into

bicarbonate (HCO3

-) and hydrogen ion (H+).

Heart failure leads to high pulmonary vascular pressure, which in turn leads to an

increase in interstitial fluid in the lungs and fluid within the alveoli. This fluid

impedes the diffusion of oxygen and carbon dioxide across the alveolar and

capillary walls,

Chapter 11

Answers to Concept Review

The central nervous system (CNS) consists of the brain and spinal cord. It sends

information to (and receives information from) the peripheral nervous system

(PNS), which consists of all of the nerves that lie outside the CNS. The PNS

collects information about the environment, sends it to the CNS and transports

output from the CNS to muscles and glands.

When a neuron receives a signal from another neuron or from a receptor, a small

graded change in membrane potential occurs. When several signals are received

at once or close in time, the graded potentials will summate, or be larger than

just a single graded potential. If the potential crosses a critical threshold, an

action potential will be generated.

During the early phase of an action potential, sodium channels open and sodium

diffuses into the neuron, causing membrane depolarization. During the second

half of an action potential the sodium channels close, potassium channels open,

potassium diffuses out of the neuron, and the membrane repolarizes.

Neuroglial cells provide physical support and protection to neurons. In the

peripheral nervous system, neuroglial cells called Schwann cells produce a

lipoprotein called myelin which insulates the neuron, speeds up the transmission

of impulses, and assists in axonal regeneration in the event of an injury.

Neuroglial cells of the central nervous system are called oligodendrocytes.

Oligodendrocytes also provide myelin, to insulate neurons and speed up

transmission of impulses, but oligodendrocytes do not assist in regeneration.

Neurotransmitters are required for an action potential in one cell to be

transmitted to another cell. They are chemicals that are released by a neuron,

diffuse across the synaptic gap, and attach to binding sites on the post synaptic

cell.

Hindbrain (movement and automatic functions), midbrain (vision and hearing),

forebrain (emotions and conscious thought).

Specific brain functions are located in specific portions of the brain. One area of

the brain receives all visual signals, for example, while an entirely different area

controls motor movements of your arm.

“Rapid eye movement” (REM) sleep is the sleep phase when we dream. It is

characterized by physiologic changes that include rapid movements of the eyes

and increases in heart rate, respiration, and blood flow.

Generally, when you get a bruise the bruised area swells. When the bruise (a

hematoma) is beneath the hard skull (i.e is subdural), it cannot swell outward.

Instead, it swells inward, exerting pressure on brain tissue. If it is severe enough

it may interfere with cerebral function.

All rights reserved.

Spinal nerves travel up and down the spinal cord and leave the spinal cord at

specific locations. Injury to the cord affects those spinal nerves below the point of

injury, not above.

Chapter 12

Answers to Concept Review

Mechanoreceptors, thermoreceptors, pain receptors, chemoreceptors, -

photoreceptors.

In receptor adaptation, the sensory neuron stops sending impulses even though

the original stimulus is still present. Oftentimes it is the unique structure of the

receptor - for example the encapsulated endings of a Pacinian corpuscle – that

allow it to adapt.

Somatic sensations provide the brain with information about temperature, touch,

vibration, pressure, pain, awareness of body movements and position.

Touch, taste, hearing, smell, sight.

Fast pain arises within a fraction of a second in response to injury from physical

pressure, heat, light, or chemicals. Fast pain generally originates from receptors

near the body surface. Slow pain originates in muscles or internal organs.

Referred pain occurs when an internal receptor sends an impulse along the same

neurons as surface pain. The brain cannot distinguish the two, so it assigns the

pain to the surface.

They transmit vibrations of the tympanic membrane (eardrum) caused by sound

to a smaller membrane called the oval window.

Skeletal muscle is found around the outside of the eye to control movement,

while smooth muscle is found inside the eye to control automatic, focusing -

functions.

Rods are highly sensitive to even very dim light. In addition, several hundred

rods may converge on a single nerve cell, further increasing our sensitivity to

dim light. However, all rods have the same photopigment, so they are not used

to distinguish colors. Cones are less sensitive to light. Only a few cones converge

on a single neuron, greatly increasing visual acuity. Individual cones have one

of three possible photopigments; this allows us to see in color.

Absorption of light by rods “uses up” the light-sensitive form of the

photopigment temporarily. After about 15 minutes in the dark, nearly all of the

photopigment molecules have been converted back to their light-sensitive form

again.

Glaucoma is caused by a build-up of pressure in the aqueous humor, which

causes compression of blood vessels in the eye. This in turn leads to a reduction

in blood flow and nutrient delivery to the eye. If it is severe enough, glaucoma

can lead to damage to the retina or optic nerve and eventually a loss of vision.

Chapter 13

ACTH stimulates the adrenal cortex; TSH stimulates the thyroid gland; FSH and

LH stimulate reproductive organs; prolactin affects the mammary glands and

milk production; growth hormone has broad effects on growth.

Hormones of the endocrine system reach nearly every cell in the body, whereas

nerves innervate only specific cells. Hormones of the endocrine system act

only on cells with specific receptors for that hormone. The endocrine system is

slower to act (seconds to months) than the nervous system (just a fraction of a

second).

Steroid hormones are lipid-soluble. They enter cells and activate certain genes,

thereby affecting the synthesis of specific proteins. Nonsteroid hormones bind

to cell membranes and either cause membrane channels to open or close, or

cause the release of a a second messenger within the cell. These actions then

turn specific cellular chemical reactions on or off, depending on the hormone.

When norepinephrine appears in a synapse and affects the transmission of an

impulse, it is a neurotransmitter. When it is in the blood being transported to

other parts of the body, it is a hormone.

In children, growth hormone stimulates the bone-lengthening activity of the

cartilaginous growth plates in long bones. At adulthood, the sex steroids cause

the growth plates to become calcified, at which point the growth plates can no

longer be stimulated by growth hormone.

The two thymus gland hormones, thymosin and thymopoietin, assist in the

maturation of T cells. Because this function is largely complete by adulthood, it

is no surprise that the thymus gland tends to shrink in adults, especially after

age 30.

The pineal has neural connections to the eyes, providing it with information

about the amount of light in the environment.

Histamine and nitric oxide are not considered true hormones because they are

not secreted into the blood and they don’t travel to all cells and tissues in the

body. They are considered local chemical messengers.

Oxytocin.

The pineal gland secretes melatonin, which helps regulate circadian or

light/dark cycles in the body. Melatonin secretion goes up during the dark

phase of our daily circadian cycle.

Chapter 14

Answers to Concept Review

Major organs of the GI tract include: the mouth, which processes food for swallowing;

pharynx & esophagus, which deliver food to the stomach; the stomach,

which stores food, digests protein, and regulates delivery to the small intestine;

the small intestine, which digests food and absorbs nutrients and water; and

the large intestine, which absorbs nutrients and eliminates waste. Accessory

organs aid in digestion and absorption, and include: salivary glands, which

moisten food and begin digestion; the pancreas, which secretes digestive

enzymes and bicarbonate; the liver, which produces bile and many chemical

functions; and the gall bladder, which stores bile.

Mechanical processing and movement, secretion, digestion, absorption,

elimination.

Saliva contains the enzyme amylase, which initiates the breakdown of starch.

Saliva also contains bicarbonate, which produces an alkaline pH in the mouth

for optimum activity of amylase.

Peristalsis is a long wave of relaxation/contraction that moves down the

intestine, pushing food forward. Segmentation is a brief contraction of just a

short segment of the intestine; its primary function is to mix food.

Humans have 32 teeth.

The three major functions of the stomach are: food storage (the stomach can

expand to a capacity of about 3 liters); digestion, specifically protein digestion

by pepsin and HCl; regulation of delivery of chyme to the small intestine.

Most of the nutrients are absorbed in the small intestine.

Fats, or lipids, contain 9 Calories/gram, proteins and carbohydrates each

contain about 4 Calories/gram.

About 1/2 to 2/3 of our daily caloric expenditure supports activities related to

our BMR, such as breathing, doing the work of all cells, and carrying out organ

functions. The remainder is for our normal minimal physical activities during

the day, not counting exercise.

Most vegetables do not contain the full range of amino acids required to build

the protein molecules we need for life. Meat, however, does.

Chapter 15

Answers to Concept Review

The kidneys regulate water levels and the concentrations of most electrolytes

(ions), including hydrogen ions. The kidneys are also responsible for the

excretion of nitrogenous wastes and for the rate of production of red blood cells

in the bone marrow. All of these actions are essential for the maintenance of

homeostasis.

The kidneys produce urine, which is sent to the bladder for temporary storage.

The urethra carries urine out of the body during urination.

The glomerular capsule receives fluid that is filtered across the glomerular

capillaries. The proximal convoluted tubule reabsorbs most of the filtered

electroytes and water; the Loop of Henle reabsorbs some salt and water and

creates the concentration gradient in the medulla that is required for water

reabsorption; the distal convoluted tubule and collecting duct reabsorb the last

of the salt and water; in these two regions reabsorption is regulated by the

hormones aldosterone (increases distal tubule and collecting duct reabsorption

of salt) and ADH (increases distal tubule reabsorption of water).

The vasa recta are long, thin blood vessels located in the medulla of the

kidneys. They serve the loop of Henle and collecting ducts.

The driving force for filtration of fluid is the blood pressure within the

glomerular capillaries. Blood pressure in the glomerular capillaries is higher

than it is in most capillaries, thereby facilitating filtration.

Water reabsorption is regulated only in the collecting duct.

The primary stimulus for the secretion of ADH is an increase in solute

concentration of the blood (a decrease in water concentration), detected by the

neurons in the hypothalamus of the brain.

Aldosterone increases the reabsorption of sodium by distal tubules and

collecting ducts.

Chronic renal failure is defined as long-term, irreversible loss of function of the

kidneys, leading to at least a 60% reduction in functioning. Acute renal failure

is short term and possibly correctable.

Once a person is in chronic renal failure (i.e. there is no hope of recovery of the

kidneys), dialysis may be required on a regular basis in order to mimic the

function of the kidneys. In the long run, the patient will need a kidney

transplant if he/she is ever to get off regular dialysis.

Chapter 16

Answers to Concept Review

Seminal vesicles, prostate gland, bulbourethral gland.

Spermatogonia divide several times by mitosis, insuring a supply of primary

spermatocytes. Meiosis produces secondary spermatocytes at the end of the

first division and then spermatids with the second cell division. The haploid

spermatids develop into mature sperm.

Fertilization usually takes place in the oviduct (fallopian tube) several hours or

even a day after intercourse.

The uterine cycle averages 28 days. During days 1–5 (menstrual phase),

estrogen and progesterone levels decline and the uterine lining degenerates,

resulting in menstruation. During days 6–14 (proliferative phase), new follicles

develop, estrogen increases, and the uterine lining proliferates. Ovulation

occurs around day 14. During days 15–28 (secretory phase), estrogen and

progesterone are secreted by the corpus luteum and the uterine lining thickens

in preparation for implantation. If there is no pregnancy, the corpus luteum

then degenerates and hormone levels drop. See Figure 16.7.

The endometrium is breaking down. Some of it is reabsorbed by the body; the

rest is expelled during the “period.” It does not break down during a pregnancy

because high levels of progesterone maintain it.

Four phases of sexual response occur in both men and women. The excitement/

plateau phase involves stimulation by sight, sounds, and physical contact. In

both sexes, neural reflexes result in dilation of blood vessels and blood flowing

into specific areas, in men into the penis resulting in swelling, lengthening and

stiffening of the organ. In women, blood flows into the labia, clitoris, and

nipples and lubricating fluids are secreted from the vagina and labia. Orgasm in

both men and women results in brief, intense pleasure with rhythmic and

involuntary muscle contractions. In men, the seminal vesicles, epididymis,

bulbourethral glands and prostate are contracted to secrete portions of semen.

Skeletal muscles at the base of the penis force sperm and seminal fluids out of

the urethra. Post orgasm results in a resolution phase with body parameters

returning to normal. A refractory period occurs in men, which prevents an

immediate erection and orgasm.

Following a period of hormonal stimulation to encourage the maturation of

eggs, several mature eggs are harvested from the woman using a needle

guided by ultrasound. Sperm is obtained from the male by masturbation.

Sperm and eggs are combined, and after several days when the eggs have

begun to divide, several embryos may be inserted into the woman’s uterus via

the vagina.

HIV, hepatitis B, genital warts.

Birth control options (* = some protection from STDs): abstinence*, surgical

sterilization, hormonal methods, IUDs, diaphragms and cervical caps, chemical

spermicides*, condoms*, rhythm method, withdrawal, morning-after pills,

abortion.

Health officials tend to worry most about STDs that cause significant disease in

the community or even deaths, as opposed to those that are minor irritants or

social embarrassments. By this measure, STDs of major concern would be HIV,

syphilis, gonorrhea, hepatitis B.

Chapter 17

Answers to Concept Review

During the S phase of cell division, the two single strands of the doublestranded

DNA unwind and “unzip”, dissociating from each other.

Complementary DNA nucleotides are then added to each single strand. DNA

polymerase facilitates the process.

Transcription occurs in the nucleus. Transcription is the process of making a

single strand of RNA that is complementary to a single gene segment of DNA.

Translation occurs in the cytoplasm. Translation is the process of making one

or more proteins, using mRNA as the template, or recipe.

Mutations are changes in the nucleotide sequence in a gene. They can be

caused by mistakes made during DNA replication, or they can be caused by

chemical or physical forces that damage DNA. DNA repair mechanisms “police”

the DNA sequence and repair most mistakes.

Prophase: nucleus breaks down, chromosomes condense and coil tightly;

metaphase: chromosomes line up chromosomes at the equator of cell;

anaphase: duplicated chromosomes separate and are pulled toward the two

poles of the dividing cell; telophase: new nuclear membranes form,

chromosomes uncoil.

Each of two cell divisions of an oocyte in meiosis produces a one viable cell and

a nonviable polar body. Each cell division of a primary or secondary

spermatocyte produces two viable cells that go on to become sperm.

Not all genes are used (expressed) all of the time. In fact, depending on the

function of the cell and the proteins it needs to carry out that function, only a

fraction of the genes will be expressed at any one time. Selective gene

expression allows a cell to make only those proteins that will assist the cell in

performing its functions and not make unnecessary proteins.

During the 8 - 32-cell stage of embryonic development the levels of oxygen,

nutrients, and cellular waste products may be different for cells in the middle of

the ball, as opposed to those on the outside. These differences may cause

differences in gene expression, ultimately leading to cellular differentiation and

specialization. As the embryo develops, environmental factors may affect the

development of tissues vital to the survival of the organism. Any alteration

from normal at this early stage may have far-reaching consequences later in

embryonic development.

Ribosomes provide a supportive base for the linkage of messenger RNA and

transfer RNA to assemble the protein. They also contain enzymes that help to

link the amino acids together.

Introns are portions of a DNA that do not contain a code for a gene, while

exons do contain a code.

Progression of a cell through its cycle is controlled at specific points by proteins

called cyclins. Cyclins activate regulatory proteins that stimulate or inhibit

events in the cell’s cycle. The most prominent checkpoints are at the end of G1,

G2, and in metaphase. External factors that also influence cell cycles include

availability of nutrients, hormones, and growth factors.

Chapter 18

Answers to Concept Review

A malignant tumor is one that has metastasized, i.e. cells have broken away

from the tumor, travelled to other sites in the body, and formed new tumors. A

benign tumor will stay in one place, that is, it does not metastasize.

The nucleus may become larger, there may be less cytoplasm, and loss of

specialized cellular function may occur. The cells lose the ability to adhere

firmly to each other and can break away and spread to other parts of the body.

A carcinogen causes a cell to take on the characteristics of a cancerous cell. In

general, carcinogens damage DNA, hastening the process of mutations. Some

of these mutations may be harmful, leading to cancer.

There is no simple screening test for lung cancer and its early symptoms are

relatively non-specific. In addition, cancer can take years to develop after

exposure to cancer-causing agents. Indeed, we are just now seeing the full

effects of the rise of in popularity of smoking over 50 years ago (review Figure

18.7).

Most skin cancers are caused by excessive exposure to UV radiation. The

energy in UV radiation can damage the DNA of skin cells.

Alcohol and high-fat diets and diets low in fiber and fruits and vegetables are

thought to contribute to colon and rectal cancers.

The immune system can recognize not only foreign cells, but our own cells that

have become “different” in some way. The immune system can recognize

certain cancerous cells and targets them for destruction.

Mos tumors are detected by various imaging techniques, including X-rays, PET

scans and MRI’s. Some types of tumors are detected by specific blood tests,

such as the PSA test for prostate cancer.

An antibody to a cancer cell antigen should target and bind only to that cancer

cell type. If chemotherapy drugs could be attached to these antibodies, it

might be an effective way to deliver the drugs directly to the cancerous cells

and nowhere else.

Know your family history; get regular cancer screenings for cancers with good

screening tests, especially for those cancers that run in your family; learn self

examination techniques; avoid direct sunlight during mid-day; control weight

and diet; don’t smoke; use alcohol in moderation, if at all; stay informed about

cancer and cancer detection.

Chapter 19

Answers to Concept Review

One copy comes from each parent.

A gene is a segment of DNA that contains the “recipe” for one or more proteins.

Alleles are different forms of homologous genes. Different alleles are likely to

have different effects (i.e. may result in different phenotypes) because they may

cause slightly different proteins to be produced.

Phenotype is what is expressed, what you see. Genotype is what is contained in

the genes on the chromosomes, whether it is expressed (seen) or not. Phenotype

is influenced by both genotype and environmental factors.

Mendel established what are still some of the most basic principles of genetics,

including the “Law of Segregation”, which holds that when gametes are formed

in the parents, each gamete gets only one allele of a gene pair, and the “Law of

Independent Assortment”, which is that (in most cases) the alleles of different

genes are distributed to egg or sperm independently of each other during

meiosis. This latter law is now only partly correct; in some cases genes that are

close together on chromosomes do tend to be inherited together.

Alterations of chromosome number can occur because of nondisjunction (failure

of chromosomes to separate during mitosis or meiosis.) Alterations in structure

can be due to deletions or translocations of pieces of chromosomes before

separation.

Dominance; when there are two alleles, one is expressed in the phenotype (i.e. is

dominant) and the other (the recessive allele) is not. Incomplete dominance; the

phenotype is halfway between what would be expressed by each allele alone.

Codominance; the products of both alleles are equally expressed in the

phenotype.

Sexual reproduction is an opportunity to re-mix and re-combine the various

alleles in the species’ gene pool. As a result, the offspring are not exactly like

either parent, nor are they precisely in-between the two parents in phenotype.

Sex-inked inheritance refers to inheritance patterns that depend on genes

located on the sex chromosomes, which are quite different between males and

females.

Dominant alleles are always expressed over recessive alleles. If a dominant

allele is lethal before reproductive age, it will not be passed on to the next

generation. Dominant lethal alleles that do exist in the population tend to be

those that do not cause death of the affected individual until after he/she has

reproduced and may have passed the dominant lethal allele on to his/her

offspring.

Genes are the recipes for proteins that may act as hormones, neurotransmitters,

enzymes, or intracellular messengers. Groups of genes and their proteins may

influence feeding, mating, learning, and possibly mood in some broad way. But

so far there is no evidence that there is a “happiness gene” or a “criminal gene”

or that “my genes made me do it!”.

Chapter 20

Answers to Concept Review

Millions of copies of short, single-stranded DNA are made, and primers are added

to one end. A mixture of the four nucleotides of DNA plus four altered,

fluorescent-labeled nucleotides is added, with DNA polymerase to synthesize

DNA. (Synthesis stops whenever the first altered nucleotide is added to any

strand.) The synthesized strands are put through gel electrophoresis and scanned

for the altered and fluorescent nucleotides arranged by size. The resulting

graphic display represents the sequence of a single strand of DNA complementary

to the original fragment of DNA.

Restriction enzymes break the bonds between specific base pairs of DNA, while

DNA ligase enzymes bind the fragments back together.

1. Isolate the DNA plasmids and the human DNA; 2. cut both DNA’s with

restriction enzymes; 3. mix the human DNA fragments with the cut plasmids; 4.

add DNA ligase to connect the fragments; 5. introduce new plasmids into

bacteria; 6. select the bacteria containing the hybrid plasmids and allow for

reproduction.

PCR is useful for amplifying a small sample of DNA for accurate identification. The

original DNA sample is unwound by gentle heating. Primers, DNA polymerase

and the four nucleotides of DNA are added, the mixture is cooled, and replication

is accomplished. Repeating the heating and cooling cycle 20 times produces more

than a million copies of the original material.

A human gene can be inserted into bacteria using plasmids. The resultant

transgenic bacteria will produce the human protein product of the human gene

Bacteria are frequently used because of their use of plasmids to exchange genes

and because of their short reproductive cycle. They have been used in human

hormone production, including insulin, growth hormone, and erythropoietin.

Genes for human proteins, such as tissue plasminogen activator (tPA) that is

used as a clot buster, have also been implanted into bacteria. Vaccines may also

be produced in this manner, such as the hepatitis B vaccine. Transgenic bacteria

are also used to produce enzymes in industrial quantities.

Transfer of the genes is more difficult in animals because they do not take up

plasmids as do plant cells, In addition, cloning an animal from a single cell is

more difficult than cloning plants from plant cells.

Implantation of the corrected gene into the appropriate cells is very difficult in an

organism with trillions of cells. Even if a correction could be made, it probably

would not be passed on to the patient’s offspring, so the disease would be

treated in just that one individual but would still persist in the gene pool.

Genes have been experimentally introduced using retroviruses that incorporate

their RNA into a host cell’s DNA through reverse transcription. The viruses can be

introduced into tissue removed from a patient, then reintroduced, or the viruses

can be injected directly into the patient.

Gene therapy has been used to some level of success in patients with SCID,

cystic fibrosis, and some cancers. Overall, though, progress in gene therapy has

been slow, lagging far behind DNA sequencing and gene identification.

Chapter 21

Answers to Concept Review

As soon as a sperm’s nucleus enters the egg, enzymes are released that make

the zona pellucida impenetrable to all other sperm. This is important because a

fertilized egg should have 46 chromosomes and only 46 chromosomes. An extra

set of chromosomes would alter the normal progression of embryonic growth and

differentiation.

After six weeks of development, a gene on the Y chromosome gene called SRY is

switched on. SRY carries the code for a protein called testis-determining factor,

which directs the initial development of the testes. Shortly thereafter the testes

begin to produce testosterone, which further stimulates the development of male

ducts and genitalia. (The embryonic testes also produces a second hormone that

suppresses development of female reproductive structures, ensuring that the

embryo develops into a male.) If no Y chromosome is present, a female fetus

develops.

The placenta functions as a selective filter for materials passing between the

mother and child. Nutrients, gases, antibodies, as well as metabolic waste from

the child and drugs from the mother pass freely through the placenta. The

placenta produces hCG, estrogen and progesterone. These hormones support the

myometrium during the pregnancy.

Stage 1: dilation of cervix to 10 cm, lasting 6–12 hours; Stage 2: expulsion of

baby (birth), lasting less than one hour; Stage 3: afterbirth, passing of placenta,

lasting half an hour.

At birth and when the umbilical cord is clamped, oxygen and carbon dioxide

exchange between mother and newborn cease. Very quickly, carbon dioxide

levels in the fetus rise. The high carbon dioxide in the fetus causes the medulla of

the infant’s brain to stimulate respiration.

The immune system of a newborn is quite immature. The schedule of

vaccinations is designed so that each vaccine is given after the immune system

has developed adequately to respond to that particular vaccination.

The pubertal period appears to be initiated by maturation of GnRH-secreting

neurons in the hypothalamus. This stimulates the secretion of LH and FSH,

initiating puberty in both sexes.

One hypothesis is that there may be an internal mechanism that determines the

timing of cell death. A second hypothesis is that accumulated cell damage or

errors may eventually limit cells’ abilities to repair themselves. A third hypothesis

is that there may be a decline in the function of a critical body system, leading to

the decline of other systems.

Most of it is due to a reduction of deaths due to accidents and disease. It does

not appear that the maximum length of human life has been extended much

(yet.)

Not all cells, organs, and organ systems die at the same time, so which system’s

death do you use to define the irreversible death of the individual? Currently,

most clinical definitions of death attempt to assess the function of the entire

brain including the brainstem, because without these, functions of the other

organ systems cannot be maintained.

Chapter 22

Answers to Concept Review

1. Descent over time; 2. genetic modification; 3. unpredictable and natural.

Fossils are preserved remnants of organisms. They consist of bones, teeth,

shells, and occasionally spores and seeds. If they are covered soon after death by

layers of sediment or ash, these become mineralized and rock-like.

Comparative anatomy and embryology, comparative biochemistry, biogeography.

Individuals and species that are best suited for their environments by virtue of

their genetic makeup are more likely to survive to reproductive age and to

reproduce. So natural selection encourages changes in the gene pool that are

likely to favor survival.

Genetic drift refers to random changes in allele frequency due to chance events.

Gene flow refers to the geographical redistribution of alleles. The genes in a

particular population can be dramatically influenced by migrations, for example,

that are not random events.

Before about 4 billion years ago the earth was hot and dry. As it cooled, water

vapor condensed as rain, water appeared, and the oceans began to form. Current

thinking is that simple organic molecules arose spontaneously and were dissolved

in the sea. Eventually the first self-replicating molecules, probably related to

single-stranded RNA, formed on templates of clay near the shoreline. That led to

DNA and proteins. At some point these self-replicating molecules became

enclosed in a lipid-protein membrane (a primitive cell membrane). The rest is (a

long) history of evolution.

At some point in evolution, primitive photosynthetic organisms (plants) began

using carbon dioxide and water to make their own energy-containing molecules,

releasing free oxygen into the environment in the process. Oxygen proved to be

toxic to many primitive anaerobic organisms. It also broke down the energycontaining

molecules in the sea. New cells and organisms evolved that could

harness and use the energy released by reactions between oxygen and energyproducing

molecules. This is exactly what modern animals do.

Hominidae walk upright and have enlarged brains.

Modern humans, or Homo sapiens probably first appeared in Africa about

140,000 to 100,000 years ago. About 50,000 years ago it appears that they

migrated through what is now Yemen and then to the rest of the planet.

With modern transportation and communication, races are no longer isolated in

their original areas. History has shown that where races are brought together,

they tend to interbreed. It may not even take 100,000 years for all humans to

share essentially the same worldwide gene pool!

Chapter 23

Answers to Concept Review

An ecosystem is a community of organisms and the physical environment in

which they live.

The carrying capacity of an ecosystem is the population that the system can

support indefinitely.

Underdeveloped countries with very little industrial base generally start with poor

living conditions and a high death rate. When living conditions improve the death

rate generally declines, the birth rate rises, and the population increases rapidly.

Over time the birth rate slowly declines until it equals the death rate. At this

point the population is stable. Regions expected to gain the most population in

the next 40 years include most of the countries in middle Africa, Latin American,

and Asia. Regions expected to gain the least include North America and northern

Europe.

Zero population growth is that point in a population at which births equal deaths.

Zero population growth can be achieved by increasing the death rate (not a good

idea) or decreasing the birth rate. Decreasing the birth rate may not be easy in

some countries because of both social and economic factors.

A climax community represents the final and most stable community possible,

given the physical conditions of the environment. Climax communities are

generally the most efficient in terms of energy usage and the most varied in

terms of numbers of species present. If disturbed, climax communities such as

old-growth forests or grassy prairies may take a long time to recover.

A constant supply of energy is necessary because according to the second law of

thermodynamics, whenever energy changes form or is transferred (as it is in the

chemical reactions that sustain life’s processes) some energy is lost, or wasted.

New energy is needed to replace the wasted energy. Ultimately, that energy

comes from the sun.

Producers such as plants capture the energy in sunlight and use it, along with

carbon dioxide and water, to make energy-storage molecules such as sugars and

starches. Consumers such as animals use the stored energy found in plants or

other animals.

Water constantly cycles between the atmosphere, ocean, and land. Water

evaporates from the ocean or lakes into the atmosphere and falls onto the land

and oceans as rain. Water is a universal solvent for many of the elements used

by living organisms.

Plants combine carbon dioxide with water during photosynthesis, creating

carbohydrates and releasing oxygen. Plants and animals then break down

carbohydrates through aerobic respiration, synthesizing other complex molecules.

This process produces carbon dioxide again. Fossil fuels and the carbon in the

shells of organisms represent a large reservoir pool of carbon.

Weathering of rocks makes phosphate available in soil where it either runs off

with surface water to supply aquatic ecosystems or is taken up by plants.

Consumers ingest the phosphate that has been synthesized by producers, and

when these organisms die and decompose, the phosphate ends up as sediment

again.

Chapter 24

Answers to Concept Review

The ozone layer in the upper atmosphere absorbs significant amounts of

ultraviolet radiation from the sun. If this radiation were to reach the earth’s

surface it would cause increased mutations resulting in increased cases of skin

cancer, cataracts, and possibly suppress our immune systems.

Acid precipitation corrodes metal and stone and damages forests and aquatic

ecosystems. Smog results in an increased incidence of chronic respiratory

illnesses, such as asthma and emphysema.

Human activities pollute the water supply with untreated sewage, chemicals from

industry, pesticide runoff, fertilizer from both farms and yards, and petroleum

products from a variety of sources. All of these pollutants can and do end up in

Earth’s fresh water supply, and many of them later end up in the oceans.

Pollution allows gases such as water vapor, carbon dioxide, methane, nitrous

oxide and synthetic gases made from chlorofluorocarbons to escape into the

atmosphere and mix with the normal atmospheric gases (primarily water vapor,

nitrogen, and oxygen). These polluting gases contribute to the insulating effect of

the atmosphere and trap heat radiating from the earth, resulting in increased

temperatures.

Each “higher” animal in a food chain tends to accumulate toxins in their tissues to

much higher concentrations than were found in the animals they ate for food.

Therefore, the highest concentrations of toxins will occur in animals higher up in

the food chain.

Sources of energy include fossil fuels such as coal, oil, and natural gas; nuclear

energy; hydroelectric power; wind power; biomass fuels such as wood or

methane produced from dung; and of course the original source of all power,

solar power.

Biodiversity refers to the variety of living organisms on Earth; in the broadest

sense it is a measure of ecological “health”. A lack of biodiversity may limit our

diet choices, reduce our ability to discover new medicines, and even the affect

the quality of the air we breathe, since the oxygen in air is provided by a rich

variety of plants.

Sustainable development is best described by a statement from the World

Commission on Environment and Development in 1987. It is “development that

meets the needs of the present without compromising the ability of future

generations to meet their economic needs”. Reaching the level of sustainable

development as soon as possible only makes sense, because the longer we delay

the more expensive it will become to meet the economic needs of future

generations.

We can consume less, recycle more, encourage sustainable agriculture, lower the

 http://wps.aw.com/bc_johnson_humanbio_5/100/25619/6558552.cw/index.html

, try to get them to slow their breathing or hold their breath momentarily a couple of times.your business. Is it half empty or hall full?

•Chemistry of Life

•Outline

•Basic Chemistry

–Elements

–Atoms

–Molecules and Compounds

•Chemical Reactions

–Ionic, Covalent, and Hydrogen Bonding

•Properties of Water

•Acids and Bases and Buffers

•Molecules of Life

–Carbohydrates, Lipids, Proteins, Nucleic acids, ATP

•Basic Chemistry

•There are 92 naturally-occurring elements.

–Over 90% of human body is composed of four elements.

vCarbon.

vNitrogen.

vOxygen.

vHydrogen.

•

•Atoms

•An atom is the smallest unit of matter that retains an element’s physical and chemical properties.

–Positively-charged protons and neutral neutrons are located in the nucleus.

–Negatively-charged electrons orbit the nucleus in shells.

•

•Molecules and Compounds

•A molecule is a group of atoms bonded together.

•A compound is a group of molecules bonded together.

•Ionic Reactions

•During an ionic reaction, atoms give up or take on an electron to stabilize their outer shells.

•Ions are particles that carry a positive (+) or negative (-) charge.

–The attraction between oppositely charged sodium ions and chloride ions forms an ionic bond.

•Ionic Reaction

•Covalent Reactions

•In covalent reactions, atoms share electrons in covalent bonds instead of losing or gaining them.

–A single bond is formed when atoms share a single pair of electrons.

–A double bond is formed when atoms share two pairs of electrons.

–A triple bond is formed when atoms share three pairs of electrons.

•Covalent Reactions

•Hydrogen Bonding

•A hydrogen bond occurs when a covalently bonded hydrogen is positive and is attracted to a negatively charged atom.

•Example: H2O, water.

–Electrons in water - more time circling larger oxygen atom than smaller hydrogen atom.

–

•Models of Water Molecules

•Hydrogen Bonding between Water Molecules

•Properties of Water Critical for Life

•Water is liquid at room temperature.

•Water is a solvent for polar molecules.

•Water molecules are cohesive.

•Water temperature rises and falls slowly.

•Water has a high heat of vaporization.

•Frozen water is less dense than liquid water.

•Density of Ice vs. Liquid Water

•

•Acids and Bases

•Acids dissociate in water and release hydrogen ions (H+).

•Bases take up hydrogen ions (H+) or release hydroxide ions (OH-).

–Buffers prevent large changes in amounts of acids and bases in body by taking up excess hydrogen ions or hydroxide ions.

•

•The pH Scale

•Molecules of Life

•Four categories of molecules are unique to cells.

–Carbohydrates.

–Lipids.

–Proteins.

–Nucleic Acids.

vATP

•

•Carbohydrates

•Carbohydrates function for quick and short-term energy storage.

–Monosaccharide (simple sugar).

vGlucose.

–Disaccharide.

vSucrose: Glucose + Fructose

•Complex Carbohydrates

•Polysaccharides.

–Starch (plants).

–Glycogen (animals).

–Cellulose (plant cell walls).

•Lipids

•Lipids contain more energy per gram than any other biological molecule.

–Do not dissolve in water.

vAbsence of polar groups.

–Fats.

vAnimal origin, solid at room temperature.

–Oils.

vPlant origin, liquid at room temperature.

•Structure of a Fat Molecule

•Saturated and Unsaturated Fatty Acids

A fatty acid is a carbon-hydrogen chain ending with -COOH.

–Saturated fatty acids contain only single bonds between the carbon atoms.

–Unsaturated fatty acids contain one or more double bonds in the carbon chain.

–There are two essential fatty acids, linoleic and linolenic fatty acid.

–

•Fatty Acid Stacking

•Trans Fats: Unnatural Fatty Acids

•How Detergents Work

•Phospholipids

•Phospholipids contain a phosphate head and fatty acid tails.

–Polar head and non-polar tails.

vSoluble in water.

•Phospholipids

•Steroids

•Steroids are lipids with a backbone of four fused carbon rings.

–Estrogen and testosterone.

•

•Proteins

•Proteins are macromolecules with amino acid subunits.

–An amino acid has a central carbon atom bonded to a hydrogen and three groups.

ØPolypeptide – Single chain of amino acids.

–

•Proteins

•Proteins

vPeptide bond - Any bond joining two amino acids.

Ø

•

•Proteins

•Amino Acids

•Amino Acids

•Amino Acids

•Amino Acids

•Essential Amino Acids

•Levels of Protein Organization

•Primary Structure.

–Linear sequence of amino acids.

•Secondary Structure.

–Polypeptide takes on orientation in space.

•Tertiary Structure.

–Final three-dimensional shape.

•Quaternary Structure.

–Proteins with more than one polypeptide.

•

•

•Nucleic Acids

•Nucleic acids are huge macromolecules composed of nucleotides.

–A nucleotide is constructed of a phosphate, a pentose sugar, and a nitrogenous base.

–Deoxyribonucleic acid (DNA).

vDouble-stranded helix.

–Ribonucleic acid (RNA).

vSingle stranded.

•Structure of a Nucleotide

•DNA Structure

•(ATP) Adenosine Triphosphate

•ATP is the primary cellular energy carrier.

–Energy currency of cells.

–Breaks down to adenosine diphosphate (ADP) and a molecule of inorganic phosphate, releasing energy to drive cellular metabolism.

•Release of Energy for Cell to Do Work

•Need to Know

1.Understanding the molecules that we are made of allows easier understanding of cellular and whole organism functions

2.Life on Earth is based on the chemistry of carbon, hydrogen, nitrogen, and oxygen

●

•Need to Know (Con’t)

3.Water is critical to life.  The properties of water that make this so are:

–Liquid at room temperature

–Solvent for charged compounds, easy reactions

–Flows freely

–Resists temperature changes

–Takes a lot of energy to vaporize

–Less dense when frozen

●

•Need to Know (Con’t)

4.Buffers help maintain acid/base stability in the body

5.Important macromolecules of life are:

–Carbohydrates: Carbon-oxygen ring structures

vQuick energy, short-term storage of energy

–Lipids: Long carbon-hydrogen chains

vLong-term energy storage

vCell membranes

vSteroid hormones (complex carbon-rings)

•Need to Know (Con’t)

5.Important macromolecules of life are (Con’t):

–Proteins: Carbon-nitrogen chains with side groups

vEnzymes for biochemical regulation

vStructural

vMovement

vDefense

vHormones

vTransportation

•Need to Know (Con’t)

5.Important macromolecules of life are (Con’t):

–Nucleic Acids: Carbon-nitrogen rings + carbohydrate ring + phosphate group

vGenes (DNA)

vProtein making blueprint (RNA)

vEnergy currency of the cell (ATP)

•Chapter 3

•Cell Structure and Function

•Outline

•The Cell Theory

•Cellular Organization

–Plasma Membrane

–Cytoskeleton

–Nucleus

–Endomembrane System

–Mitochondria

•Cellular Respiration

–Fermentation

•The Cell Theory

•Let’s face it, life is totally cellular (this does not refer to the mobile phone)

•The cell theory states:

1.Cells are the basic unit of life

2.All living things are made up of cells

3.New cells arise only from preexisting cells

•Cellular Organization

•Plasma membrane surrounds the cell and regulates entrance and exit of substances.

–Nucleus is the centrally located structure containing chromosomes and is the control center of the cell.

–Cytoplasm is the portion of the cell between the nucleus and plasma membrane.  Consistency: semifluid gel, like wet Jello.

•Cellular Organization

–Organelles are small membranous structures, each with a specific function.

–Cytoskeleton is a network of interconnected filaments and microtubules in the cytoplasm that maintain cell shape.

•

•Plasma Membrane

•Plasma membrane is a phospholipid bilayer with attached or embedded proteins.

–Polar head and non-polar tails.

vForm spherical bilayer when placed in water.

–Plasma membrane proteins form receptors, conductors, or enzymes in metabolic reactions.

•Plasma Membrane Model

•Plasma Membrane Functions

•Plasma membrane is selectively permeable, and regulates movement of molecules and ions across the cell membrane.

–Diffusion is the random movement of molecules from an area of higher concentration to an area of lower concentration until they are equally distributed.

–Osmosis is the random movement of water from an area of higher concentration to an area of lower concentration

•Plasma Membrane Functions

•Plasma Membrane Functions

•Plasma Membrane Functions

•Plasma Membrane Functions

•Plasma Membrane Functions

•Plasma Membrane Functions

–Transport by Carriers.

vFacilitated transport occurs when a molecule is transported across the plasma membrane down a concentration gradient.

vActive transport occurs when a molecule is moving against a concentration gradient with the input of energy.

•Active Transport

•Plasma Membrane Functions

–Other mechanisms for moving things in or out of cell

vEndocytosis occurs when a portion of the plasma membrane invaginates to envelop a substance and then pinches off to form an intracellular vesicle.

vExocytosis occurs when a vesicle fuses with the plasma membrane as secretion occurs.

•Endomembrane System

•The Cytoskeleton

•The cytoskeleton is formed of several types of filamentous structures that give the cell its shape and organelles the ability to move about the cell.

–Actin Filaments

–Microtubules.

•The Nucleus

•The nucleus stores genetic information that determines body cell characteristics and metabolic functioning.

–Contains nucleolus: site of ribosome formation.

–Contains chromatin: uncoiled DNA

–Nucleus is separated from the cytoplasm by a nuclear envelope.

vContains nuclear pores to permit passage of proteins and ribosomal subunits.

v

•Nucleus and Nuclear Membrane

•Ribosomes

•Ribosomes are found singly or in groups (polyribosomes) in the cytoplasm.

–Function in protein synthesis.

•The Endomembrane System

•Endoplasmic Reticulum.

–System of membranous channels and saccules.

vRough ER is studded with ribosomes and synthesizes proteins.

vSmooth ER synthesizes phospholipids, as well as various other functions.

•The Endomembrane System

•The Golgi Apparatus.

–Consists of a stack of three to twenty curved saccules, along with vesicles.

vModifies proteins that bud from the ER.

•Lysosomes.

–Membranous sacs produced by the Golgi apparatus that contain hydrolytic digestive enzymes.

•Endomembrane System

•Mitochondria

•Mitochondria are double-membrane organelles involved in cellular respiration.

–Site of ATP production.

•Cellular Metabolism

•Cellular metabolism includes all the chemical reactions that occur in a cell.

–Often organized into metabolic pathways.

vMost regulated by feedback inhibition.

•Enzymes and Cofactors

•Enzymes are proteins that speed up chemical reactions, the participating reactants are called the enzyme’s substrates.

•Enzymes are catalysts and are not used up and are recycled.

–Many enzymes require cofactors or helper molecules for assistance.

vMany vitamins are cofactors

•Enzymatic Action

•Cellular Respiration

•Cellular respiration refers to the process by which the cells generates energy to do work.

•Glucose breakdown requires three sub-pathways.

–Glycolysis.

–Citric Acid Cycle (Krebs cycle).

–Electron Transport System.

•Altogether, the breakdown of one glucose molecule results in 36 ATP molecules.

•Cellular Respiration

•Fermentation

•Fermentation is an anaerobic (without oxygen) process that results in the buildup of lactate.

–Lactate is toxic to cells and causes muscle cramps and fatigue.

–Only produces two ATP per glucose molecule.

•Need to Know

1.Cell Theory- Understand the three parts of the theory:

A.Cell: Basic unit of life

B.Living things are made of cells

C.New cells only come from other cells

2.General cellular organization

A.Cell membrane

B.Nucleus

C.Cytoplasm

D.Organelles

E.Cytoskeleton

•Need to Know (Con’t)

3.Plasma membrane structure & function

A.Phospholipid bilayer

B.Embedded proteins- functions

C.Selectively permeable- regulates molecules movements across bilayer

D.Mechanisms of transport

1.Diffusion- free movement across plasma memb.

2.Osmosis- refers to movement of water

3.Facilitated- carrier protein, no energy used

4.Active- carrier protein, energy required

5.Endocytosis- engulf, bring in big things

6.Exocytosis- release cell produce to outside

4.Cytoskeleton- provides structural support

A.Actin filaments

B.Microtubules

●

•Need to Know (Con’t)

5.Nucleus

A.Control center for the cell

B.DNA resides there

C.Surrounded by nuclear envelope

D.Site of ribosome formation

6.Endomembrane System

A.Rough endoplasmic reticulum (ER) has ribosomes- site of protein synthesis

7.Mitochondria

A.Site of ATP production, cellular respiration takes place here

•Need to Know (Con’t)

8.Enzymes

A.Critical to functioning of the cell

B.Speed up chemical reactions

C.Are not used up but are recycled

9.Cellular Respiration

A.Process by which cells produce energy to do work, metabolic or mechanical

B.Electron transport system; most important part of system

C.Breakdown of one glucose molecule produces 36 ATP

•Chapter 4

•Organization and Regulation of Body Systems

•Outline

•Tissue Types

–Epithelial

–Connective

–Muscular

–Nervous

•Integumentary System

•Body Cavities

•Organ Systems

•Homeostasis

•Types of Tissues

•A tissue is composed of similarly specialized cells that perform a common function.

–Categorized into four groups.

vEpithelial: covers body surfaces and lines body cavities.

vConnective: binds and supports body parts.

vMuscular: moves the body and its parts.

vNervous: receives stimuli and conducts nerve impulses.

•Epithelial Tissue

•Epithelial tissue consists of tightly packed cells forming a continuous layer that serve in protection, secretion, absorption, excretion, and filtration.

–Named according to shape of cell.

vSquamous - Flattened.

vCuboidal - Cubed.

vColumnar - Column.

•Epithelial Tissue

•Connective Tissue

•Connective tissue serves many functions including binding organs, providing support and protection, and producing red blood cells.

–Cells are separated by matrix of fibers.

vCollagen fibers.

vReticular fibers.

vElastic fibers.

•Connective Tissues

•Connective Tissue

•Fibrous Connective Tissue

•Loose Fibrous and Dense Fibrous Tissues.

–Loose fibrous connective tissue supports epithelium and many internal organs.

vAdipose Tissue.

ØFat storage

–Dense fibrous connective tissue is made of tightly-packed collagen fibers and is found in tendons and ligaments.

•Supportive Connective Tissue

•Cartilage.

–Cells lie in lacunae separated by solid, flexible matrix.

vHyaline cartilage.

vElastic cartilage.

vFibrocartilage.

•Supportive Connective Tissue

•Bone.

–Most rigid connective tissue composed of matrix of inorganic ions, mostly calcium.

vCompact bone.

vSpongy bone.

•Fluid Connective Tissue

•Blood: matrix is made of plasma, not cells.  Transports nutrients, oxygen, and wastes.

vBlood is composed of:

ØPlasma.

ØFormed Elements.

§Red blood cells.

§White blood cells.

§Platelets.

•Blood

•Blood

•Muscular Tissue

•Muscle (contractile) tissue composed of muscle fibers.

–Contain large quantities of proteins called actin filaments and myosin filaments.

–Three types of muscle fibers.

vSkeletal muscle.

vSmooth muscle.

vCardiac muscle.

•Muscular Tissue

•Nervous Tissue

•Nervous tissue has three functions.

–Sensory input.

–Data integration.

–Motor output.

•Neuron (nerve cell) composed of three parts.

vDendrites.

vCell body.

vAxon.

•Neuroglia service and support neurons.

•Neuron and Neuroglia

•Integumentary System

•The integumentary system (skin) is the collection of skin tissues and accessory cell types that function as an organ.

–Skin plays a significant role in maintaining homeostasis.

vWater Loss.

vTemperature.

–Synthesizes certain chemicals.

vVitamin D.

•Integumentary System

•Regions of Skin.

–Epidermis.

vStratified squamous epithelium.

–Dermis.

vCollagen and elastic fibers.

vLies beneath epidermis.

ØSubcutaneous layer lies below the dermis and is composed of loose connective tissue and adipose tissue.

•Human Skin Anatomy

•Body Cavities

•Ventral cavity divided into two parts.

–Thoracic cavity.

–Abdominal cavity.

•Dorsal cavity divided into two parts.

–Cranial cavity.

–Vertebral cavity.

•Organ Systems

•Maintenance of the Body.

–Digestive system.

vReceives and digests food.

vAbsorbs nutrients, eliminates wastes.

–Cardiovascular system.

vTransports nutrients and oxygen.

vHelps control temp., fluid, pH balance.

–Lymphatic system.

vHelps control fluid balance.

vAbsorbs fats.

vDefends against disease.

•Organ Systems

•Maintenance of the Body.

–Respiratory system.

vBrings oxygen in and takes carbon dioxide out.

–Urinary system.

vRids body of metabolic wastes.

vHelps control fluid balance.

•Organ Systems

•Support and Movement.

–Skeletal system.

vProtects body parts.

vSupports, helps move the body.

vStores minerals, produces red blood cells.

–Muscular system.

vMoves body parts.

vProduces heat.

•Organ Systems

•Coordination and Regulation of Body Systems.

–Nervous system.

vReceives sensory input, integrates and stores input.

vInitiates motor output.

vHelps coordinate organ systems.

–Endocrine system.

vProduces hormones.

vHelps coordinate organ systems.

•Organ Systems

•Continuance of the Species.

–Reproductive system.

vProvides ability to reproduce.

•Homeostasis

•Homeostasis is the relative constancy of the body’s internal environment.

–Fluctuation around a particular value (a set point).

vMaintained by negative feedback.

ØBrings about reversal of the change.

§Activated by deviation from set point.

vPositive feedback brings about greater change in same direction

•

••Need to Know

1.Types of tissues: general functions

A.Epithelial: body surfaces

B.Connective: binds, supports body parts

C.Muscular: movement

D.Nervous: input, output, integration, system control

2.Three types of epithelial cells

A.Squamous

B.Cuboidal

C.Columnar

•Need to Know

3.Types and functions of connective tissues

A.Loose fibrous: binds internal organs

B.Dense fibrous: tendons and ligaments, movement

C.Supportive: cartilage, support, lubrication

D.Supportive: bone, support and protection

E.Fluid connective tissue: blood, nutrient and gas transport

4.Three types of muscule tissue

A.Skeletal: voluntary

B.Smooth: involuntary

C.Cardiac: involuntary

•Need to Know

5.Nervous tissue

A.Functions: sensory input, data integration, motor output

B.Three parts to a neuron

1.Dendrite

2.Cell body

3.Axon

6.Organ Systems: general features

A.Digestive

B.Cardiovascular

C.Lymphatic

•Need to Know

6.Organ Systems: general features

D.Respiration

E.Urinary

F.Skeletal

G.Muscle

H.Nervous

I.Endocrine

J.Reproductive

7.Homeostasis

A.Understand how negative feedback works

B.Understand how positive feedback works

•Chapter 5

•Skeletal System

•Outline

•Functions of the Skeletal System

•Tissues of the Skeletal System

•Bone Remodeling and Repair

•Bones of the Skeleton

•Articulation

•Homeostasis

•Functions of the Skeletal System

•Support body.

•Protect soft body parts.

•Produce blood cells.

•Store minerals and fat.

•Permit flexible body movement.

–

•Tissues of the Skeletal System

•Bone: produced by ossification- incorporation of calcium salts into extracellular matrix.

–Compact bone is highly organized and composed of tubular osteons.

vOsteocytes lie in lacunae, tiny chambers arranged in concentric circles around a central canal.

–Spongy bone contains numerous plates (trabeculae) separated by unequal spaces.

vSpaces are often filled with red bone marrow.

•

•Tissues of the Skeletal System

•Cartilage

–Cartilage is flexible because the gel-like matrix contains collagenous and elastic fibers.

–Three types differ according to type and arrangement of fibers.

vHyaline - Firm and flexible; end of long bones, the nose, end of ribs, trachea, in the knee

vFibrocartilage – Strong; between vertebrae,

vElastic – Flexible; ear flaps, epiglottis

•Tissues of the Skeletal System

•Fibrous Connective Tissue

–Made of rows of fibroblasts separated by bundles of collagenous fibers.

vMakes up ligaments (connect bone to bone) and tendons (connect muscles to bones).

•Bone Growth and Repair

•Cells involved in bone remodeling and repair.

–Osteoprogenitor cells form inner portion of periosteum; give rise to osteoblasts.

–Osteoblasts take calcium from blood and form new bone.

–Osteocytes maintain bone.

–Osteoclasts break down bone, remove worn cells, assist in depositing calcium in the blood.

•Bone Fracture and Repair

•

•Axial Skeleton: Bones of the Skull

•Axial Skeleton: Bones of the Face

•Axial Skeleton: Vertebral Column

•Axial Skeleton: The Rib Cage

•The rib cage is composed of the thoracic vertebrae, ribs and associated cartilage, and the sternum.

–Twelve pairs of ribs.

vAll connect to thoracic vertebrae in back.

vUpper seven pairs (true ribs) connect to sternum by costal cartilage.

vNext three pairs (false ribs) attach to sternum by common cartilage.

vLast two pairs (floating ribs)do not attach to sternum.

•Axial Skeleton: Thoracic Vertebrae and Rib Cage

•Appendicular Skeleton: Bones of Pectoral Girdle and Arm

•Appendicular Skeleton: Bones of Pelvic Girdle and Lower Limb

•Articulations

•Bones are joined at joints.

–Fibrous joints: sutures between cranial bones; immovable.

–Cartilaginous joints: hyaline cartilage/ connect ribs to sternum or fibrocartilage/ intervertebral disks; slightly movable.

–Synovial joints separate the bones by a cavity/ fluid lubricated; completely movable.

vHinge: knee, elbow

vPivot: twisting wrist

vBall-and-socket: leg/hip, arm/shoulder

•Knee Joint

•Homeostasis

•Rib cage enables oxygen to enter bloodstream.

•Red bone marrow produces red and white blood cells.

•Jaw and teeth chew food, aiding digestion.

•Bones protect internal organs.

•Calcium storage.

•Efficient locomotion.

•Need to Know

1.Functions of the skeletal system and homestasis

A.Must know the functions from slide 3.

B.Homeostatic mechanisms skeletal system is involved with; slide 20.

2.Tissues of the skeletal system

A.Bone: ossification- incorporation of calcium into matrix

B.Bone types

1.Compact bone: highly organized, dense, thick

2.Spongy bone: made of plates with many spaces; spaces have red bone marrow- production of red blood cells

•Need to Know

2.Tissues of the skeletal system

C.Cartilage

1.Hyaline: know consistency and where found

2.Fibrocartilage: know consistency and where found

3.Elastic: know consistency and where found

D.Fibrous connective tissue

1.Ligaments: connect bone to bone

2.Tendons: connect muscle to bone

•Need to Know

3.Bone growth and repair

A.Osteoblasts: make new bone; take calcium from the blood

B.Osteocytes: maintain bone

C.Osteoclasts: break bone down; put calcium into blood

4.Rib cage

A.General structure: connected to vertebrae at back and by cartilage to sternum in front

B.Organization good for process of breathing

•Need to Know

5.Articulations

A.Fibrous: immovable; examples

B.Cartilagenous: slightly movable; examples

C.Synovial: completely movable; examples

1.Hinge: example

2.Pivot: example

3.Ball and socket: example

Text Box: Lab partners:

______________________________________________________

Lab 3 - Macromolecules & Nutrition

OBJECTIVES

Identify the monomers of proteins, lipids, carbohydrates, and nucleic acids. 

Assay for proteins, starch, sugars, and lipids in foods.

Understand the nutritional roles of proteins, lipids, and carbohydrates.

Determine the nutritional content of food by analyzing its nutrition label.

Analyze the nutritional value of a diet using computer software.

INTRODUCTION

Every organism in the world is made of four types of chemical compounds: proteins, lipids, carbohydrates, and nucleic acids.  Each type of organic molecule plays particular roles.  ________________ do work and help provide structure within cells.  ________________ store energy, provide insulation, and act as messages.  ______________________ also store energy and provide structure.  _________________ store genetic information, act as energy currency in cells, and act as messages.  Each type of molecule is important for life.

Three macromolecules—proteins, lipids, and carbohydrates—make up the majority of every organism and are important nutritionally. Nucleic acids are not as important nutritionally (our cells can build them from other molecules), but they play a vital role in passing on traits from ____________ to offspring, directing the organization of other macromolecules, and transporting energy within cells.  In this lab, you will test for the three nutritionally important macromolecules.

It is important to remember that macromolecules, as the name implies, are large.  They are usually composed of repeated monomers (smaller chemical compounds).  Proteins are made of long, folded strands of _____________________.  Carbohydrates include simple sugars and the large polymers cellulose, glycogen, and starch.  Simple sugars are made of one, two or three ___________________linked together.  Cellulose, glycogen, and starch are all made of many __________ molecules linked together in a particular way for each polymer.  Lipids include fats, oils, and steroids.  They cannot all be easily broken down into simpler parts.  Lipids do not dissolve in __________________.

You will test for the presence of lipids, proteins and amino acids, starch, and simple sugars in several substances. For each assay, there must be a way to recognize whether the substance being tested for is present, and in approximately what quantity.  This is accomplished by setting up negative and positive controls or a standard for comparison.  A positive control includes the substance being detected.  A negative control includes everything in the positive control except for the substance being detected.  A standard is used when the assay may return a range of values.  The standard includes samples of the full concentration range of substance that may be detected.

Activity 1. -- Assaying for Organic Macromolecules

In this activity you will learn how to test for the presence of various organic macromolecules. Then you will determine if these macromolecules are present in several other solutions of foods.  Your instructor will assign solutions to you.

Before you begin this activity, make a guess as to what are the solutions that you have been assigned.  Which of these macromolecules do you think is part of this solution?  Write your predictions in this table.  Use “yes” or “+” to predict that the component is present and “no” or “-“ to predict that it is not present.

Solution

might be:

Protein ?

Starch?

Sugars?

Lipids?

Materials:

4 test tubes

biuret solution in  dropper bottles

transfer pipettes

albumin solution

2 unknown solutions

BIURET TEST

The Biuret Test assays (tests) for the presence of proteins.  The dye reacts with the peptide bonds that hold adjacent amino acids together in a protein.  The dye itself is light blue.  In the presence of peptides (short chains of amino acids) it turns slightly purple.  In the presence of proteins (long chains of amino acids) it changes to a purple-violet color.  To perform the Biuret Test:

Mark 4 test tubes at 3 cm from the bottom.  Use a transfer pipette to fill each tube with a test solution to this mark.

Add a few drops of the Biuret solution to each tube.

Gently shake or roll tube between your palms several times to mix the fluids.

Wait three minutes then check the color.  Hold a white paper directly behind the tube when examining the color.

Conduct this procedure with water, dilute egg white (albumin protein), and the two solutions assigned to you.

What are the positive and negative controls for this test?

Fill in this table with the contents of each test tube:

Test tube

Contents

Result: color

Describe the final appearance of each test tube in the table above.

When would this test give you inaccurate results?  In other words, when would the results not allow you to determine the presence or absence of proteins in the sample?

Materials:

5 test tubes

iodine dye

transfer pipettes

starch, glucose solutions

two unknown solutions

B. IODINE TEST

Iodine Test assays for the presence of starch.  Either Lugol’s solution or I2KI, both of which contain potassium and iodine, can be used as the indicator dye.  In the presence of starch, both dyes turn blue-black.  To perform the Iodine Test:

Place a few mL of your substance into a small test tube.

Add two or three drops of the dye.

Check for a blue-black color.  Don’t forget to use a white background.

d.  Conduct this test on water, 1% glucose, 1% starch, and your two unknown solutions.

Which solutions are the positive and negative controls?

What information will you learn by testing a solution of glucose?

Fill in this table with the contents of each test tube:

Test tube

Contents

Result: color

Describe the final color of each solution in the last column of the table above.

When would this test give inaccurate results?

Materials:

500 mL beaker, hot plate

reverse action pliers

7 test tubes

Benedict’s reagent

transfer pipettes

sugar solutions, your unknown solutions

C. BENEDICT’S TEST

Benedict’s Test assays for the presence of simple sugars.  The light blue dye reacts with mono- and disaccharides in the presence of heat to form a colored precipitate (solid).  The precipitate may be green, yellow, orange or red, depending on how much sugar is present.  This test does not detect sucrose, because sucrose’s chemical structure does not let it react with Benedict’s reagent.

To perform the Benedict’s Test:

Fill a large (500 mL) beaker half full with tap water.  Add a few boiling chips.

Bring the water to a boil on a hot plate.  Use CAUTION with hot solutions and burners.

Mark 7 test tubes at 2 cm and 6 cm above the bottom.  BE SURE TO LABEL YOUR TEST TUBES with the solution to be tested Before filling them.

Put 2 mL of your test solution in a test tube, using the 2 cm mark as a measurement tool.  Repeat with each of the solutions listed in the table below.  Add Benedict’s reagent to the second mark on the test tubes.

Place the test tubes in the boiling water bath and leave it for 5 minutes.

Remove the test tubes from the boiling water bath using reverse action pliers.  USE CARE!  Place them in a test tube rack to cool for at least 5 minutes..

Observe the color of the solution and check for the color and amount of any precipitate at the bottom of the tube.

For this assay, make standards that include a tube with 1% glucose, a tube with 0.01% glucose, a tube with 1% starch, and a tube with 1% sucrose.  Don’t forget to include a negative control.  What solution should this be?

Fill in the table below with the contents of each test tube

Tube

Contents

Results

1 - Control

2

1% glucose

3

0.01% glucose

4

1% sucrose

5

1% starch

6 unknown

7 unknown

Conduct this assay on all 7 tubes (they can be boiled at the same time if the tubes are carefully labeled) and describe completely the results for each solution in the table above.

When would this test give misleading results?

D.  BROWN PAPER BAG TEST FOR LIPIDS

Materials:

Brown paper bag

Vegetable oil

test substances

The brown paper bag test assays for the presence of lipids.  Brown paper turns translucent in the presence of lipids.  To perform the brown paper bag test:

Place a tiny drop of the substance on a piece of brown paper bag.

Rub the drop in.

Let the paper dry completely.  This may take 10 minutes or more.

Check to see if the paper is translucent where you put your substance.

Why must you wait until the brown paper dries before observing the result?

Fill in the table below to describe the substances used for the positive and negative controls for this test.

Substance on bag

result

Positive Control

Negative Control

unknown

unknown

When would this test give inaccurate results?                                              

Hint: are lipids soluble in water?

Make a table that summarizes your results with the unknown solutions.  Use + and – to indicate whether the indicated macromolecule was detected.  Multiple +++ will indicate a high concentration of that molecule.

Solution

Protein ?

Starch?

Sugars?

Lipids?

14.  Now compare your results with the predictions that you made at the beginning of this activity.  Describe this comparison for each macromolecule.

15.  Suggest possible explanations for any discrepancies between your predictions and your results.

Materials:

Oil, plastic cup

Potato flakes, weigh boats

Sugar, 25 mL beaker

Powdered milk, baggie

scale

Activity 2. –  Lunch Experiment

In this experiment, you will examine the nutritional content of typical lunches eaten by yourself and your classmates.

16.  Give a general description of what you ate for lunch today or on a typical day, eg, peanut butter and jelly sandwich, celery sticks, 2 cups of 2% milk and a peppermint candy. ____________________________________________

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

17.  For the meal described above, record the nutritional information below.  You may find this information on a nutrition label on the food item, or you may need to look it up in a reference book or online.

Hint: Nutrition labels do not usually list separately the polysaccharide content of a food.  Only the amounts of total carbohydrate, sugars, and fiber are listed.  Consider the relationship between carbohydrates, starch, fiber, and sugar to determine a way to calculate the starch and glycogen content of a food item.

Food item

Lipids (g)

Starch (g)

Sugars (g)

Protein (g)

TOTALS

18.  Add up the total amount of lipids, starch, sugar, and protein in your lunch.  Record these numbers in the appropriate locations in the chart above.

Using macromolecule substitutes, prepare a “visual nutrient” lunch as described below.  Be sure to tare the electronic scale with your container on it before adding your macromolecule substitute.  Taring a scale means setting it to zero.   If you don’t tare the scale, you will be weighing your container as well as the substance you want to measure.  To tare a scale:

Turn on your scale

Place your empty container on the scale

Press the zero or tare button

Wait for the digital display to read zero.

Be sure to put each substance in the correct container.  The container will be one visual cue as to which nutrient is represented.

food molecule:                        represented by:              in this container:

Lipids

Oil

Plastic cup

Starch

Potato flakes

Baggie

Sugar

Sugar

50 mL beaker

Protein

Powdered milk

Weigh tray

Place the four containers of your “nutrient lunch” on the designated lab bench on a piece of paper labeled with the letter assigned by your instructor.  Write the lunch contents on a list provided by the instructor.

19.  When everyone is done, your instructor will show the list of all the lunch contents .  Try to match each real lunch with its nutritional content, as displayed on the lettered papers.

Lunch contents

sample-guessed

sample-correct

Tuna sandwich, milk, pickle, cookie

A

C

20. What was unexpected about any of the nutritional values of the lunches?

______________________________________________________________

_____________________________________________________________________________________________________________________________________________________________________________________________

Activity 3: Dietary Analysis:

In order to function, organisms need to eat not only the major biological macromolecules but also vitamins and minerals.  In this exercise you will combine the information you have learned in earlier sections of this lab to analyze your diet for one 24 hour period.

22.  Record everything you consume for one 24 hour period in the table below (don’t forget to include drinks):

What you ate or drank

How much you ate or drank (cups, ounces, grams)

23.  Locate a dietary analysis calculator online.  Several dietary analysis tools are listed in the reference section of this lab.  Run the calculator using your food intakes.  Print out the analysis and attach it to the end of this lab.

24. What organization publishes the dietary analysis calculator you used?  ________________________________________________________

25.  What biases do you think this group might have? ________________

___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

26. What information did your dietary analysis calculator ask about you before it analyzed your diet? _________________________________

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

27. Is there other information it didn’t ask for that you think influences your dietary needs?  Describe this information.

__________________________

____________________________________________________________

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

28. How would this additional information influence your dietary needs?

 ____

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

29.  How did your macromolecule intake compare with the recommendations (more, less, same)?

Lipids: _______________________________________________

Starch: _______________________________________________

Sugar: ________________________________________________

Protein: _______________________________________________

30. What other nutritional information did the dietary analysis tool analyze? ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Choose one of the micronutrients (vitamins, minerals, etc…) either that your dietary analysis program analyzed or that you would have liked it to analyze.

31. Which micronutrient did you choose? ___________________________

32. In what foods is this micronutrient found? _________________________

33.  What happens if you eat too much of this nutrient? __________________

____________________________________________________________________________________________________________________________________________________________________________________

34. What happens if you eat too little of this nutrient? ­­­­­­­­­­­___________________

____________________________________________________________________________________________________________________________________________________________________________________

35. Are there any groups of people that should be especially careful about this micronutrient? Why? __________________________________________

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

REFERENCES

Dickey, J.  (2003) Laboratory Investigations for Biology, 2nd ed, B. Cummings, CA.

Diamond, K. (2005) Laboratory Manual for Biology, College of San Mateo, CA.

References for Dietary Analysis:

http://www.fitday.com

http://www.mypyramid.gov

http://www.lifeclinic.com

http://www.nutrawatch.com

http://www.nutridiary.com

http://www.nat.uiuc.edu

http://www.nutritiondata.com

INTRODUCTION

The chemical reactions necessary for life occur very slowly without enzymes.  To keep an organism alive, the reactions must be sped up as much as hundreds-fold faster, at body temperatures. Enzymes act as catalysts, or substances that increase the rate of a reaction without being used up or changed themselves.  Enzymes bind to substrates and lower the energy of activation needed for the reaction to occur and make products.  Since enzymes are not consumed or altered by their reactions, one enzyme molecule can catalyze their specific reaction for hundreds and thousands of times.

Enzymes are proteins (or protein derivatives).  Proteins are made of subunits called _____________ which are linked together by peptide bonds.  Each enzyme typically can speed up only one reaction.  The shape of an enzyme determines which substrates it can bind to at its active site and, therefore, which reaction it will catalyze.  The shape of a protein can be altered by various environmental conditions.  Changing the shape of a protein is called _________________.   If the shape of an enzyme is changed, the enzyme may no longer act as a catalyst.   Three things that can change the shape of a protein are __________________, _________________, & salt concentration.

The activity of an enzyme can be altered by many factors.  A protein can only speed up a reaction when it comes into contact with the substrates (also called reactants).  Two ways (among several others) to change the likelihood that an enzyme will encounter its substrates are reaction temperature and concentration of the enzyme.

When the temperature of a solution is increased, the individual molecules move around more whereas, when the temperature of a solution is decreased, the individual molecules move around less (Hint: think about boiling and freezing water).  The more the molecules move around, the more likely it is that the enzyme will encounter its substrates.  High temperature can also affect the shape of the protein by causing the “ungluing” of hydrogen bonds that help provide 3D shape.

Secondly, when the concentration of enzyme is increased, the number of enzyme molecules relative to the number of substrate molecules increases/decreases.  If there are more/fewer enzyme molecules available, the likelihood that an individual enzyme molecule will encounter its reactants increases.  (Circle the correct answer in each pair of italicized words.)

H2O2 (peroxide) is toxic for most living organisms. Many organisms are capable of enzymatically destroying the H2O2 before it can do much damage. H2O2 can be converted to oxygen and water, as follows:

2 H2O2 ® 2 H2O + O2

Although this reaction occurs spontaneously, enzymes increase the rate considerably. At least two different enzymes are known to catalyze this reaction: catalase, found in animals and protists, and peroxidase, found in plants.

A great deal can be learned about enzymes by studying the rates of enzyme-catalyzed reactions. The rate of a chemical reaction may be studied in a number of ways including:

measuring the rate of appearance of a product (in this case, O2, which is given off as a gas)

measuring the rate of disappearance of substrate (in this case, H2O2)

measuring the pressure of the product as it appears (in this case, O2).

In this experiment, you will measure the rate of enzyme activity under various conditions, such as different enzyme concentrations, pH values, and temperatures. It is possible to measure the concentration of oxygen gas formed as H2O2 is destroyed using an O2 Gas Sensor. If a plot is made, it may appear similar to the graph shown.

At the start of the reaction, there is no product, and the concentration is the same as the atmosphere. After a short time, oxygen accumulates at a rather constant rate. The slope of the curve at this initial time is constant and is called the initial rate. As the peroxide is destroyed, less of it is available to react and the O2 is produced at lower rates. When no more peroxide is left, O2 is no longer produced, and the line displaying O2 concentration is flat.

In these experiments, you will compare the initial rate of reaction under various environmental conditions.  These factors make up the environment in which enzymes exist inside cells.

MATERIALS

Computer with Logger Pro

3.0% H2O2

Vernier computer interface

enzyme suspension               

O2 Gas Sensor

three 18 ´ 150 mm test tubes

25 mL graduated cylinder

ice

400 mL beaker

pH buffers

three dropper pipettes

test tube rack

250 mL Nalgene bottle

Thermometer or temperature probe

Figure 1

Activity 1 - Testing the Effect of Enzyme Concentration

1.      Hypothesis: How will varying the concentration of catalase affect the rate of the reaction?    As you generate this hypothesis, think about the role of enzymes in chemical reactions.

2.      Make a specific prediction, based on your hypothesis.  For example: If the concentration of catalase is increased by two-fold, then the rate of the reaction will increase four-fold.  State your prediction here:

PROCEDURE            

3. Obtain and wear goggles.

4.   Connect the Oxygen Gas Sensor to the computer interface. Prepare the computer for data collection by opening the file “06A Enzyme (O2)” from the Biology with Computers folder of Logger Pro.  Make sure the scale for time (x-axis) is in minutes and for oxygen concentration (y-axis) the values include 18-25%.  Watch the instructor’s demonstration.

5a. Using a graduated cylinder, measure 25 mL  of fresh 3% H2O2  into a 100 mL beaker.  Add 25 mL of distilled water.  Use this as your stock reaction solution for experiments on enzyme concentration and temperature.

5b.  Place three test tubes in a rack and label them 5, 10, and 20. Fill each test tube with 6 mL of the 1:1 diluted H2O2.

Initiate the enzyme catalyzed reaction with this quick series of steps.

Using a clean transfer pipette, add 5 drops of enzyme suspension to test tube 1.  (Keep your supply of enzyme solution on ice.)

Begin timing with a stopwatch or clock.

Cover the opening of the test tube firmly with a finger and gently invert the test tube once.

Pour the contents of the test tube into a clean 250 mL Nalgene bottle.

Place the O2 Gas Sensor into the bottle as shown in Figure 1. Gently push the sensor down into the bottle until it stops. The sensor is designed to seal the bottle without the need for unnecessary force.

When 15 seconds has passed from initiation, Click  to begin data collection.  If results do not show on your graph, try using Autoscale from the Graph Option menu (double click on the graph to get this menu).

When data collection has finished, remove the O2 gas sensor from the Nalgene bottle. Rinse the bottle with water and dry with a paper towel.

Adjust your graph, if needed, with the Autoscale function.  Move your data to a stored run. To do this, choose Store Latest Run from the Experiment menu.

Collect data for test tubes 10 and 20 by running the reaction in each of these tubes, one at a time:

Add 10 drops of the enzyme solution to test tube 10. Repeat Steps 6 – 8.

Add 20 drops of the enzyme solution to test tube 20. Repeat Steps 6 – 8.

Using the mouse, select the initial linear region of your data on the graph. Click on the Linear Fit button, . Click  and a best-fit linear regression line will be shown for each run selected. In Table 2, record the value of the slope, m, for each of the three solutions. (The linear regression statistics are displayed in a floating box for each of the data sets.)  Note: Each curve should be regressed individually, since the duration of the initial rate likely differs among treatments.

To print a graph of enzyme concentration vs. O2 volume showing all three data runs:

Label all three curves by choosing Text Annotation from the Insert menu, and typing “5 Drops” (or “10 Drops”, or “20 Drops”) in the edit box. Then drag each box to a position near its respective curve. Adjust the position of the arrow head.

Select “Print graph” and switch format to landscape, so the graph will fill one sheet.  Check Preview before printing, or just print one copy initially.

Print a copy of the graph, with all three data sets and the regression lines displayed. Enter your name(s) and the number of copies of the graph you want.

WAIT – Don’t leave this data set yet.  Determine the rate of reaction for each of the time intervals listed in Table 3 using the procedure outlined in Step 10. Record the rates for all three data runs in Table 3.  You do not need to print any of these regressions.

Activity 2 - Effect of pH on catalase activity

In this experiment, you will determine the effect of pH on the rate of formation of O2 by catalase.  Most enzymes have an optimum pH at which they act most effectively.  The shape of an enzyme determines how it interacts with substrates.  How can pH affect the shape of an enzyme?

13.  Hypothesis: How will the pH of the reaction solution affect the rate of this reaction?   As you generate this hypothesis, think about where catalase is naturally found.  What is the pH of its normal environment?  How can you find out?______________________________________________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________

Prediction:  State what results you expect from this experiment, based on the idea(s) stated in your hypothesis.  Be specific and consider the pH range that you will be using (pH 4, 7, and 10). Use the If …./then … format. _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Procedure

Be sure your safety goggles are on.

Place three clean test tubes in a rack and label them pH 4, pH 7, and pH 10.

Add 3 mL of 3% H2O2 (not your diluted stock) and 3 mL of a pH buffer to each test tube, as in Table 1.

Table 1. Setup for pH effect on catalase

pH of buffer

Volume of 3% H2O2 (mL)

Volume of buffer (mL)

pH 4

3

3

pH 7

3

3

pH 10

3

3

Using the test tube labeled pH 4, add 10 drops of enzyme solution and repeat Steps 6 – 8 from the first experiment on catalase concentration.

Using the test tube labeled pH 7, add 10 drops of enzyme solution and repeat Steps 6 – 8.

Using the test tube labeled pH 10, add 10 drops of enzyme solution and repeat Steps 6 – 8.

Repeat Steps 10 and 11 to calculate the rate of reaction and print your graph, showing all three reactions with their regression lines.  Record the reaction rate for each pH value in Table 

Cleanup: Solutions should be rinsed down the sink drain.  Wash all test tubes. Use the alcohol solution to wipe off the labeling. Place tubes upside down in the drying rack.

Activity 3 – Effects of temperature on catalase activity

In this experiment, you will determine the effects of temperature on the rate of formation of O2 by catalase.   Review the Introduction to find a description of two ways that temperature can affect enzyme activity: (Note: this does not refer to effects of high versus low temperatures).

21.______________________________________________________________________________________________________________________________

22.______________________________________________________________________________________________________________________________

23. Hypothesis: How will the rate of the reaction differ when the reaction solution is kept at different temperatures?  Consider the two factors that you just listed.  As you generate this hypothesis, think about where catalase is naturally found._________________________________________________­­­­­­­­­­___________ _____________________________________________________________________________________________________________________________________________________________________________________________________

_________________________________________________________________

24. Prediction:  State what results you expect from this experiment, based on the idea(s) stated in your hypothesis.  Be specific and consider the temperatures that you will be using (read the instructions below). Use the If …./then … format. __________________________________________________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________

Your teacher will assign a temperature range for your lab group to test, using three replicate test tubes.  Plan to share your results with the rest of the class.  Depending on your assigned temperature, set up your water bath as described below. Place a thermometer in your water bath (not in the reaction vessel) to assist in maintaining the proper temperature.  Add hot water during the test as needed to maintain the temperature.

0 – 5°C:  500 mL beaker filled with ice and water.

20 – 25°C: 500 mL beaker filled with room temperature water.

30 – 35°C:  500 mL beaker filled with very warm water.

50 – 55°C:  500 mL beaker filled with hot water.

enzyme heated to 100°C (boiled for 5 minutes) then cooled to room temperature for the reaction.

25.   Rinse the three numbered test tubes used for Part I. Fill each test tube with 6 mL of your stock 1:1 diluted H2O2. Place the test tubes in the water bath. The test tubes should be in the water bath for 5 minutes before starting the reaction. Ideally, preincubate the Nalgene reaction bottle at the same temperature as the corresponding test tubes.  Record the temperature of the water bath, as indicated on the thermometer or with the temperature probe, in the space provided in Table 5.

26.   Find the rate of enzyme activity for test tubes 1, 2, and 3.  Keep the water bath at the correct temperature during each test.

Ø  Add 10 Drops of the enzyme solution to test tube 1. Repeat Steps 6 – 8.

Ø  Add 10 drops of the enzyme solution to test tube 2. Repeat Steps 6 – 8.

Ø  Add 10 drops of the enzyme solution to test tube 3. Repeat Steps 6 – 8.

27.   Regress each data set (Step 10) and record the reaction rate for each data set in Table 5. Calculate and record the average rate in Table 5.

28.   Record the average rate and the temperature of your water bath from Table 5 on the class data table. When the entire class has reported their data, record the class data in Table 6.

Temperature Shift experiment (optional)

Move the tubes from the 0ºC water bath to the 30 – 35°C water bath, then immediately record the rate of oxygen production, as done previously.

29. On Page 2 of this experiment file on the laptop, create a graph of the rate of enzyme activity vs. temperature. Plot the rate values for the class data in Table 5 on the y-axis, and the temperature on the x-axis.  Use this graph to answer the questions at the end of the lab.

DATA

Part I Effect of Enzyme Concentration

Table 2

Test tube label

Slope, or rate (%/min)

5 Drops

10 Drops

20 Drops

Table 3

Time intervals (Minutes)

Rates

0-0.5 min

0.5-1.0 min

1.0-1.5 min

1.5-2.0 min

2.0-3.0 min

5 Drops

10 Drops

20 Drops

Part II Effect of pH

Table 4

Test tube label

Slope, or rate (%/min)

pH 4

pH 7

pH 10

Part III Effect of Temperature

Table 5

Table 6 (Class Data)

Test tube label

Slope, or rate (%/min)

Temperature tested

Average rate

Trial 1

Trial 2

Trial 3

Average

Temperature range:____°C

QUESTIONS

All questions must be answered by every student, using class data if you did not perform that experiment.  In addition, you must write a full conclusion for one of the experiments: enzyme concentration, pH, or temperature.  Follow the directions below.

Part I Effect of Enzyme Concentration

Describe the results shown in Table 2.  How does changing the concentration of enzyme affect the rate of decomposition of H2O2?

What do you think will happen to the rate of reaction if one increases the concentration of enzyme to twenty-five drops? Will it be 5 times as fast as the 5-drop reaction?  EXPLAIN.

From Table 3: At what time point is the reaction rate highest? Explain why.

From Table 3: At what time point is the reaction rate lowest? Why?

Part II Effect of pH

Now examine your data as presented in your graph.  Write one paragraph in which you describe how the reaction rate changed (or not) at different pH.   Describe your results, but save any interpretation for the Conclusion.

Why does changing the pH affect the rate of enzyme activity?

Part III  Effect of Temperature

Now examine your data as presented in your graph (Step 29).  Write one paragraph in which you describe how the reaction rate changed (or not) at different temperatures. 

Does this follow a pattern you anticipated?  Compare to your prediction.

Why might enzyme activity decrease at very high temperatures?

What might explain any enzyme activity in the treatment with boiled enzyme?

Conclusion

Write a complete conclusion for one activity of your experiment (enzyme concentration, pH, or temperature) on a separate sheet of paper and add it to this lab.  Include the following points:

Discuss how your results support or disprove your hypothesis.  Does the relationship that you predicted match your results?  Is this true for all the data points?  You cannot ignore data simply because they do not support your hypothesis.

Do you have any reason to doubt the validity of your results?  Did anything occur during the experiment that makes you think these results may not be valid or repeatable?

How would you change your experimental design to improve it?

Do these results suggest another hypothesis?  If so, state the hypothesis.

What importance does this conclusion have for your reader?

Review Questions

From the temperature experiment, assume high rates of activity in a reaction tube that was shifted from 0ºC to 35ºC.  How might this be explained, assuming that little or no activity was found in the tube heated to 100°C?

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Use the results of this experiment to explain why it is so dangerous to get overheated or to get a very high fever.

___________________________________

_____________________________________________________________________________________________________________________________________________________________________________________________

Ancient human bodies have been found relatively intact in acid bogs.  Based on factors affecting enzyme activity, explain how these bodies have been preserved all this time. _______________________________________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________

Directions for preparing frozen vegetables usually tell you not to thaw them before cooking, but to place them directly into boiling water.  Based on the results of the temperature experiment, explain why this cooking technique produces better quality food. ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

extensions

Different organisms often live in very different habitats. Design a series of experiments to investigate how the same enzyme from different types of organisms might affect the rate of enzyme activity. Consider testing a plant, an animal, and a protist.

Presumably, at higher concentrations of H2O2, there is a greater chance that an enzyme molecule might collide with H2O2. If so, the concentration of H2O2 might alter the rate of oxygen production. Design a series of experiments to investigate how differing concentrations of the substrate hydrogen peroxide might affect the rate of enzyme activity.

Design an experiment to determine the effect of boiling the catalase on the rate of reaction.

REFERENCES and ACKNOWLEDGEMENTS

Morgan & Carter (2005) Investigating Biology Laboratory Manual, 5th edition. Pearson Education, Inc.

Masterman, D and K. Redding. (2006) Biology with Computers, 3rd Ed. Vernier Software and Technology, OR

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