Review Sheet
AP Biology
Exam 4 will cover:
Chapter 8: ALL
Chapter 9: ALL
Water Potential Lab
Water Potential Problems
Water potential problems under Notes section
Videos:
http://vcell.ndsu.nodak.edu/animations/
(on the left – all relating to cell resp)
Chapter 8:
ENERGY and the laws that govern its transfer
1. What is energy?
2. Describe the two major types of energy and give examples.
3. Identify and describe the two forms of potential energy (PE) discussed in class. You
should be able to explain the connection between the four forces of the universe and
energy.
4. What gives a substance like glucose energy?
5. Describe the first law of thermodynamics. Why can’t I create energy (why can’t I give
something the ability to accelerate without losing some of my own energy)?
7. Describe all the energy transfers that occur starting with you standing next to a tennis
ball on the floor, you pick up the ball, you drop it, it bounces a few times and eventually
stops. Make sure you describe where the energy started and where it went throughout
(follow the ability to accelerate).
8. What does the 1st law of thermodynamics tell us about the total energy in the universe?
9. Describe the second law of thermodynamics and the implications of this law in terms
of entropy.
10. Explain why if I throw a ball to you, 100% of the energy that I put into the ball is not
transferred to you. Where does the energy go since it can’t be destroyed?
11. Explain why your shoes, clothes, ipod, cell phone, computer, dishwasher, oven,
refridgerator, car, wii, xbox and everything else will eventually break, in terms of the 2nd
law. Do not just say that things get more disordered with every energy transfer. Why does
this happen? Define order.
12. What is order? Disorder? Why does matter tend to “disorder” with energy transfers in
terms of probability?
13. What does the 2nd law tell us about our own life? What will happen to the DNA in our
cells over time regardless of how well our enzymes are at repairing it?
14. The 2nd law also dictates that energy goes from concentrated to dispersed. Likewise, it
goes from useful to less useful. Give an example of this in your life. Be very specific.
15. How are we able to generate the desired or ordered state if the universe is always
getting more disordered? What has to happen whenever order (a particular arrangement
of matter) is generated or forced like keeping our atoms in the arrangement that they are
to live?
16. In order for your proteins to keep yourself ordered, you have to take in food. Some of
this food will be burned in cell respiration and the energy transferred into ATP as
discussed in class. Why do we need to keep eating in order to maintain order in our
bodies? For all the order your body maintains, you must be generating more disorder
around you. Explain how this is happening. Where is the disorder? How is your body
generating disorder around you as you sit here and read this?
17. Why can’t we win? Why can’t we continue to maintain the ordered state and live
forever?
18. If you wanted to preserve something that you love like an old doll, how would you do
this and why? Hint: How do we store the declaration of independence?
19. What is the energy source for 99.9% of life on this planet? Basically, if I track back
my body’s ability to accelerate, where did this ability come from? Explain in general
terms how you got this ability form that source. Go back to the forces.
20. We concluded in class that we are constantly fighting the 2nd law of thermodynamics
whether it is fixing items that break, buying new items to replace broken ones, or trying
to prevent items from breaking like putting those rubber cases around ipods and iphones
so that the rubber cases take the energy transfers and get disordered instead of your
phone, or painting your house every so many years, etc... Our bodies are doing the same
thing: our proteins are constantly repairing their homes (cells), and certain cells that have
too much damage and are thrown out (apoptosis), you have enzymes that eliminate toxic
chemicals to prevent damage, and your cells will divide to replace those that have been
lost. All of this repair and maintenance requires matter to be accelerated in a specific
manner and therefore requires energy (ATP). The point of saying this is that it appears
that the 2nd law is terrible, but there is a silver lining. Explain the upside.
21. Why is reproduction so important in light of the 2nd law of thermodynamics?
22. Compare and contrast endergonic to exergonic reactions. Under which would you put
the overall reaction of photosynthesis? Cell respiration? Explain both.
23. Compare the PE of the reactants to the products for the two reactions (endergonic and
exergonic). For example, ATP  ADP + Pi ; This reaction is exergonic as the phosphate
on ATP has the ability to accelerate (you should know why). Therefore, energy is lost to
somewhere. Where does the energy (ability to accelerate) go?
24. Define Gibbs Free Energy (G).
25. Define G.
25. What sign does G have when describing an exergonic process? What about an
endergonic process? Explain.
26. What two variables must be measured to determine free energy changes in systems?
Explain how these relate to G.
27. If H is negative and S is positive, what does this tell you? Explain why.
28. If H is positive and S is negative, what does this tell you? Explain why.
29. You should memorize the G for cell resp, ATP synthesis, ATP hydrolysis and
photosynthesis.
30. Describe what is meant by energy coupling and give an example in terms of G.
31. What happens when you reverse an endergonic reaction like putting a phosphate onto
ADP? What type of reaction do you get? What happens to G when you reverse a
reaction? Why?
32. Explain the following energy coupling examples (identify the exergonic process and
the endergonic process): 1. lifting a book off the ground, 2. Dropping the book, 3. Water
moving through a dam spinning turbines, 4. A gas powered engine, 5. Active transport
using a transporter protein like in figure 5.18, 6. Electrons moving from glucose to
oxygen allowing a phosphate to be placed on ADP to make ATP.
33. Explain fire (burning wood). Follow the energy flow. How does this compare to cell
resp?
34. Be able to draw the structure of ATP.
35. In class we said that one glucose can be used to make 36 or 38 ATP molecules.
Compare the amount of energy in the glucose to that in the 36 ATP in terms of G. You
should be able to calculate this on the test. Explain the discrepancy.
36. Why use ATP? Why not just use glucose or amino acids or triglycerides or sucrose or
fatty acids directly as a source of energy?
37. How efficient is the production of ATP from glucose? What law of thermodynamics
does this observation support? Explain.
38. Which yields more ATP, glucose or triglycerides? Explain why.
39. After the third phosphate of ATP has been transferred to a protein, causing a
conformational change, what is the fate of the resulting ADP?
40. How many ATP are used per second per cell? 10,000,000 per cell per second on
average. That means this many are made and used per second!
41. Identify at least five endergonic reactions in the cell that must be powered using the
exergonic reaction of ATP hydrolysis.
42. Why do we breathe in air for molecular oxygen (O2)?
43. Describe the three major fates of the food that you eat. Which are exergonic and
which are endergonic? Which are catabolic and which are anabolic?
44. Are glucose and triglycerides the only molecules you can use as an energy source?
Explain.
45. In class we determined two major problems with chemical reactions in terms of life.
First is that exergonic reactions typically happen way too __________________. The
second is that the desired reaction may not be the reaction that occurs. We said that
glucose + glucose + glucose… typically results in the formation of glycogen in animal
muscle and liver cells, but it could also become cellulose in plants. It of course depends
on the glycosidic linkage that is formed between carbon 1 and carbon 4 of the glucose
molecules. Therefore, to make sure the desired reaction occurs faster than the undesired
ones, a cells needs…
HOW ENZYMES WORK
46. What is an enzyme?
47. Explain why enzymes CANNOT, by themselves, catalyze endergonic reactions like
putting a phosphate onto ADP. What would this enzyme need to allow this reaction to be
catalyzed?
48. What reaction does carbonic anhydrase catalyze? What is the rate per enzyme? What
cofactor does this enzyme require? How is this cofactor held in place? What is the
significance of this cofactor? Know the reaction mechanism.
49. What is activation energy? If you push a boulder off a cliff and it falls 300 feet
smashing a car below, what was the activation energy? Explain activation energy.
50. Explain how enzymes lower the activation energy of a reaction. Be specific.
51. Be able to graph a reactions progress over time from products to reactants in terms of
energy for both exergonic and endergonic reactions. You should be able to label
everything like Ea, G, etc…
52. Describe how an enzyme works starting with the binding of substrate(s) to the release
of product(s). Use the detail general overview of enzyme catalysis review slide. Be sure
to explain how they lower activation energy. This is extremely important!
53. Compare the lock and key to the induced fit model of enzyme catalysis. Which is the
current model? Why does this one make more sense? (You should know the hexokinase
example).
54. Construction workers use hammers in order to catalyze the specific reaction of
hammering nails into wood. This is analogous to what in proteins?
55. Describe the two general types of cofactors and give examples of each. Are cofactors
only used by enzymes? Explain.
56. Discuss the structure and function of hemoglobin. Where is it located? How many per
cell? Etc… What cofactor does hemoglobin require to function? Explain why if you do
not get enough iron in your diet, you will become anemic (have a reduced ability to carry
oxygen in your blood) on the molecular level.
57. When you eat, you are basically eating for monomers to build with (biosynthesis) and
to burn for energy. However, you also need the so-called vitamins and minerals. What are
these? How do they relate to protein cofactors?
58. Aside from heme and Zinc, we discussed two other cofactors, NAD+ and FAD. What
vitamins are required to synthesize these cofactors. Describe the structure of NAD+ and
FAD. You should know the full name of each. Describe how their names are related to
their structures. Describe the function of these two cofactors.
59. What is an enzymatic reaction rate? What factors affect reaction rates? You should
know all five factors discussed. I could ask you to graph for example the rate of a
reaction as I increase/decrease substrate concentration, enzyme concentration,
temperature, pH, salt, etc…Make sure you can explain why this is happening logically.
60. Sometimes we revert back to illogical reasoning and think that all enzymes function
best at body temperature and pH 7. Explain why this is far from the truth.
61. What would you hypothesize the optimal salt (NaCl) concentration to be for a human
protein? Why? What happens if salt gets too high? Too low? Answer the same questions
for temperature and pH.
61. Explain why, logically, enzymes or enzyme pathways need to be regulated (need to
be turned on and off). Give examples.
62. Compare competitive to non-competitive inhibitors.
63. Describe how allosteric regulation works and discuss the PFK example as well as the
hemoglobin example.
64. Describe the other methods of enzyme inhibition/activation discussed in class.
65. Explain how enzyme inhibition is taken advantage of by humans to treat disease.
Give a few examples.
66. If you wanted to design an inhibitor of an enzyme of a bacterium that causes a certain
disease and you wanted it to be a competitive inhibitor, what might you try first (what
might you base it on)?
67. Explain how enzymes are typically activated during signal transduction and signal
amplification. What is signal amplification and how does it work?
68. Explain how phosphorylation can be used to both inhibit and activate different
enzymes.
69. What is the name given to the type of enzyme that catalyzes phosphorylation.
70. What is meant by an enzyme pathway? How are enzyme pathways typically
regulated?
71. What type of reaction do dehyrogenases typically catalyze and what cofactors are
typically involved?
72. Compare negative feedback to positive feedback and give examples of both. Which is
more stable (which would you use to maintain homeostasis of some substance?). Explain
why.
73. Describe how negative feedback and allosteric regulation come together at PFK in
glycolysis.
74. How many different reactions does a single enzyme typically catalyze?
CHAPTER 9 Cell Resp
ESSAY QUESTION that will be on the exam:
a. Starting with food on your kitchen table and oxygen in the air, explain how
cells convert the stored chemical potential “energy” in food to stored chemical
potential “energy” in ATP. Draw a diagram to accompany your explanation if you
wish. Be as specific as possible. Make sure you discuss affinity, reduction,
oxidation, all of the energy transfers and when exergonic processes power
endergonic processes (energy coupling). You need specific numbers for ATP
used/made and NADH/FADH2 made for every step.
(The following terms MUST be properly included: ETC, chemiosmosis, oxidative
phosphorylation, electron carriers, heme, cytochrome c, ubiquinone, complex I, complex II,
complex III, complex IV, mitochondria, NAD+, NADH, citrate, citrate synthase, hexokinase,
phosphofructokinase, G3P, FAD, FADH2, glycolysis, glucose, cytosol, inner mitochondrial
membrane, outer mitochondrial membrane, preparatory phase, energy payoff phase,
intermembrane space, ATP synthase, oxygen, digested, ATP, ADP, P i, H+(protons),
electrochecmiacl gradient, cristae, Coenzyme A, pyruvate, Krebs, cytoplasm, substrate, product,
intermediate, glucose transporter, reduced, oxidized facilitated diffusion, grooming, CO2, kinetic
energy, potential energy, energy coupling, heart, blood, lungs, protein complex, final electron
acceptor, electronegativity, active transport, endergonic, exergonic, affinity, substrate level
phosphorylation, matrix, acetyl-CoA, electrons, G3P, OAA, decarboxylation, enzymes and water.)
1. Explain how breathing (respiration) is related to cellular respiration.
2. If we breathe in to capture O2 for cell resp and breathe out to get rid of the metablic waste from
cell resp (excretion of CO2), how is it that CPR can work?
3. Compare the efficiency of humans converting the energy in glucose to the energy in ATP to a
car converting the energy of gasoline into the KE of the car. Why is ATP production only 40%
efficient? Where does the other 60% of the “energy” go?
4. What is all the ATP that is made used for? How much ATP is made per cell per second on
average?
5. How much of our ATP is used for general housekeeping (non-voluntary functions) and how
much for voluntary activity?
6. Give five examples of ATP being used in a cell.
7. What is meant by a calorie/joule (what is the definition)?
8. How does a food calorie compare to an actual calorie of energy?
9. Describe the structure and function of both NAD+ and FAD.
10. Compare oxidation to reduction. In class we said you could never have one without the other
and hence the term redox reaction. Explain why this is?
11. Write out the overall reaction for cell respiration (you should have this in memory). Identify
what is being oxidized and what is being reduced.
12. Explain why glucose has chemical potential energy.
13. What is going on inside a fire? What is a fire?
14. How does cell respiration link to photosynthesis?
15. Compare cell respiration to just lighting glucose on fire with a match. What is similar and
how are the two different?
16. Describe the two ways by which ATP can be made. Why are they given the names that they
are given?
17. Describe how chemiosmosis and an electrochemical gradient are involved in oxidative
phosphorylation of ADP to ATP. Define the two underlined terms.
18. Identify the three stages of cell respiration.
19. Explain what is meant by intermediates.
20. Describe the main purpose for doing glycolysis and Krebs in the presence of oxygen.
21. Describe the main purpose of the ETC.
22. Compare the ETC to a dam like the Hoover dam. How are they similar?
23. Where do all the carbons of glucose end up and at what point during cell respiration do they
come out?
24. Photosynthesis and cell respiration is going from water to water. Explain what I mean by this.
25. In the ETC, protons are being pumped from low to high concentration. Where do they get the
“energy” to do this?
26. Know your ETC inhibitors (Figure 6.13). You should be able to explain how they work and
why they cause a problem. For example, why would DNP be an excellent weight loss drug?
27. It turns out that you need only very small amounts of vitamin B3 (niacin), which is used to
make NAD+. The same goes for riboflavin, the vitamin used in the synthesis of FAD. However,
you have incredible numbers of both FAD and NAD+ in your cells. How can you explain this?
28. Figure 6.14 is critical. You should know how many ATP and NADH/FADH2 are being
used/made, where they go, etc…
29. If you inhibit the ETC with something like carbon monoxide, glycolysis and Krebs will also
stop. Explain why inhibiting the ETC would also cause these two processes to shut down.
30. Explain how you could experimentally determine that glucose will become CO2 and O2 will
become water.
31. Compare active transport, facilitated diffusion and simple diffusion. Give real examples in the
cell.
32. Explain why glycolysis and Krebs require so many enzymes. Why can’t there just be a single
enzyme that converts glucose to two pyruvates?
33. Explain which parts of cell respiration (glycolysis, Krebs, ETC) would be negatively affected
by generating holes in the inner mitochondrial membrane. How about if large holes, big enough
for proteins to pass through, were placed in both the inner and outer membranes of the
mitochondria?
34. Why is it important that the mitochondria have a double membrane?
35. What is the importance of cristae in terms of cell respiration?
36. In general terms explain how the energy in glucose is transferred to the energy in ATP. Where
do the electrons from glucose go? What are these moving electrons used to do? Etc…
37. Go through the powerpoint. I put tons of annotations in this year, which I am hoping will help
you. Read and understand everything. Do not just memorize, it will get you in trouble on the test.
38. Watch the ETC video over and over again.
39. What would happen in the absence of oxygen to cell respiration in cells that rely on oxygen as
the final electron acceptor of the ETC?
40. Compare and contrast strict aerobes, strict anaerobes and facultative anaerobes. Give
examples of each.
41. Compare aerobic respiration to strict anaerobic respiration (this is NOT
fermentation).
42. In class we said that strict anaerobes will use the Kreb’s cycle and ETC (anaerobic
respiration). How is that possible if they cannot use molecular oxygen (O2)?
43. What is fermentation? What do we call organisms/cells that can use oxygen if
present, but switch to fermentation when absent? What is the purpose of fermentation?
Basically, what is the reason why organisms convert pyruvate to either lactic acid or
ethanol? Why not just get rid of the pyruvate? What enzyme pathway is common to both
aerobic respiration and fermentation? What parts of aerobic respiration are turned off
during fermentation? Compare lactic acid fermentation to alcohol (ethanol) fermentation
and give examples of organisms that use each.
44. Explain how brewers make beer and wine using alcohol fermentation. Explain how
yogurt is made using lactic acid fermentation.
45. What is the fate of the pyruvate secreted into the blood by our muscle cells under
anaerobic conditions?
46. Explain why bread rises and has characteristic tiny “air pockets” in it.
47. What is lactic acidosis and what might this be an indication of?
48. We said in class that nobody goes around eating monomers of gluose. Make sure you
understand figures 6.16 (catabolic) and 6.17 (anabolic), which shows how the
macromolecules that you eat be broken down and either burned to form ATP from ADP
and Pi, or converted into other types of monomers to make other polymers.
49. Discuss the two fates of food not including storage.
50. Explain why a triglyceride can be burned to make more ATP than glucose.
51. Lets say your cells are running low on the amino acid alanine. Explain how your body
would make the missing amino acid using stored fat. Additionally, explain how the sugar
you eat can be converted into stored fat (triglycerides).
53. Over the vacation I went on a diet and lost ten pounds. Where did most of that mass
go?
STUDY WELL