AP BIOLOGY NOTES ON CHAPTER 9 – CELLULAR RESPIRATION

I. Review and overview of energy processes

II. Catabolism, reduction and oxidation in cellular respiration

Check your understanding:1. Use the following terms correctly in a sentence: redox reactions, reduction, oxidation,

reducing agent, oxidizing agent.2. Why does “reducing“ a substance gives that substance more potential energy.3. In cellular respiration, what is being reduced, what is being oxidized.4. Describe the role of electron carrier molecules in cellular respiration.

III. Stages of cellular respiration

Check your understanding:

5. Draw and label the parts of the mitochondrion.6. Describe the main purpose and conditions of each stage of cellular respiration7. Differentiate between substrate-level phosphorylation and oxidative phosphorylation.8. Design an experiment that could be used to measure the rate of cellular respiration in a living

organism.9. Explain the benefit of slow glucose breakdown instead of rapid breakdown of glucose during

cellular respiration.10. Analyze the graphs below (next page):

a.

b.

IV. Glycolysis:

V. The Intermediate Stage (Pyruvate grooming)

Check your understanding:

11. What is being oxidized and reduced in glycolysis?12. What is being oxidized and reduced during the intermediate steps?13. The enzyme phosphofructokinase, which catalyzes one of the steps of glycolysis, is a key point

for regulating glycolysis. ATP is the allosteric regulator of this enzyme. Would you expect ATP to be an inhibitor or an activator of this enzyme (consider the end products of glycolysis)?

14. What happens with the NADH molecules after glycolysis and the intermediate step?15. What happens with pyruvate after glycolysis?16. What happens with the ATP after glycolysis?17. What happens with the CO2 that is produced during the intermediate step?

VI. The Citric Acid Cycle:

Check your understanding:

18. Why can the citric acid cycle be used as an evidence of common origin of life?19. NADH is an inhibitor of several enzymes of the citric acid cycle. Why is this beneficial for living

organisms? What type of enzyme regulation is this?20. What happens with the FADH2 and NADH that are produced in the citric acid cycle?21. What happens with the ATP and CO2 that are produced in the cycle?22. Is ATP production a substrate-level phosphorylation or oxidative phosphorylation here?23. How do aerobic bacteria perform this process?

VII. Oxidative phosphorylation

Check your understanding:

24. Why is the double membrane structure of the mitochondrion important?25. What provides the energy for ATP synthesis in this process?26. What is being oxidized and reduced in this process?27. The following experiment was performed with mitochondria that have only an inner

membrane. Explain the experimental setup and the results on the graph.

28. Where does the oxygen come from? What is its role in this process?29. The experiment below shows the effect of gold nanoparticles on ATP synthase activity. Write

a brief analysis of the results. (next page)(Figure A)30. Is carbon from glucose used in OP? For what purpose?31. What do you think would happen if you decreased the pH of the intermembrane space of the

mitochondrion in the absence of O2?32. Cyanide poisoning blocks certain parts of cellular respiration. Look at the collected data on

patients with cyanide poisoning and try to determine what part of cellular respiration would be blocked: (next page)(Figure B)

Figure A

Figure B:

metabolite Average Patient Levels (µM) Normal Levels (µM)Glucose 99 100Pyruvate 27 25NAD+ 10 75NADH 400 50

VIII. Fermentation

Check your understanding:

33. What is the overall purpose of fermentation, why does it have to occur?34. What is a facultative anaerobe? 35. Design an experiment that would produce the following data. After analyzing the data, write

a brief conclusion.

36. List two other factors besides the type of sugar that can influence the rate of fermentation.37. List some benefits and disadvantages of fermentation.38. What is the role of NADH in fermentation?

IX. Connection to other metabolic pathways

Check your understanding:

39. What types of macromolecules could be used for cellular respiration?40. How can these molecules enter cellular respiration?41. What happens with the macromolecules that we consume but not use immediately for

energy?42. What might happen to a muscle cell that used up its supply of ATP and oxygen?