Bio 181, Fall 2005

Dr. Lisa Werner

Learning Objectives for Chapter 9, How Cells Harvest Energy

Understand and be able to use the following terms:

photosynthesis	cellular respiration	oxidation	reduction
redox	oxidizing agent	reducing agent	coenzyme
NAD+/NADH	FAD/FADH2	electron transport chain	substrate level phosphorylation
oxidative phosphorylation	glycolysis	citric acid cycle	Krebs cycle
acetyl coA	chemiosmosis	ATP synthase	anaerobic
fermentation	ethanol	lactic acid	beta-oxidation
AMP	phosphofructokinase	citrate

1. Describe energy flow and chemical cycling in ecosystems.

2. Give the role of ATP in energy metabolism. How is energy in stored in ATP, and why is it so readily usable?

3. For what types of processes do cells require ATP?

4. Explain the principle of redox and explain the role of redox reactions in the breakdown of organic molecule to produce energy for the cell.

5. What is the role of NADH and FADH₂ in the cell? Be able to give the oxidized and reduced forms of these molecules.

6. Name and be able to describe the two ways of making ATP from the catabolism of organic molecules.

7. List the stages of aerobic respiration. Where in the cell does each occur?

8. Describe what happens in glycolysis. What are the products of glycolysis? What happens next to the products of glycolysis if oxygen is present? If oxygen is not present? How many net ATP are produced per molecule of glucose?

9. What types of cells use glycolysis?

10. Describe what happens in the oxidation of pyruvate. What are the reactants? What are the products?

11. Describe the citric acid cycle. What are the reactants? What are the products?

12. What is the electron transport chain? Describe the process of chemiosmosis and how it is used to make ATP. What is oxygen used for?

13. For each molecule of glucose, how many ATP are made using aerobic respiration? For each stage of aerobic respiration (glycolysis, citric acid cycle, oxidative phosphorylation), be able to give the number of ATP, NADH and FADH₂ made, and explain how this translates to the total yield of ATP.

14. Give or recognize the overall equation for aerobic respiration. Be able to explain what happens to the glucose, and where the carbon dioxide molecules are produced; and how the oxygen is used and the water produced.

15. What is the purpose of fermentation?

16. What types of fermentation are there? What cells undergo these types of fermentation?

17. What molecules regulate the rate of aerobic respiration in the cell, and what effect do they have?

18. How does the cell use other organic molecules for energy? (i.e. protein, fats, and other carbohydrates besides glucose) How are they catabolized so that they can feed into aerobic respiration? What stages do they feed into?