Cellular Respiration: Harvesting Chemical Energy

Chapter 9

1. Explain the difference between oxidation and reduction reactions. Be sure to mention the changes in energy that accompany these reactions.

2. What is the role played by NAD⁺ and dehydrogenase enzymes in cellular respiration?

3. What is meant by substrate level phosphorylation? Give an example.

4. Basically, what is happening to the molecules in the citric acid cycle?

5. What is the basic purpose of the citric acid cycle?

6. In which molecules is most of the energy from the citric acid redox reactions conserved? How will these molecules convert their energy to a form that can be used to make ATP?

7. Is the phosphorylation reaction in the Krebs cycle substrate level or oxidative?

8. What is it about fat molecules that make them a more energetic fuel than carbohydrates?

9. How is the structure of the mitochondrion suited to its function?

10. As electrons are passed along the ETC they lose energy. Where does this energy go?

11. Explain chemiosmosis and the proton-motive force.

12. What is the final electron acceptor in aerobic respiration? What is formed?

13. What is the value of fermentation? Describe one example.

14. Think of the NADH formed during glycolysis. What is the final acceptor of its electrons during fermentation? What is the final acceptor during respiration?

15. Why is glycolysis considered to be an ancient catabolic pathway?

16. Under what conditions can lactate accumulate in vertebrate muscle cells?

17. Describe the control of cellular respiration and state why that control is beneficial.