9.1 Cellular Respiration: An Overview

Understand Key Concepts

1. Cells use the energy available in food to make a final energy-rich compound called

   1. water.

   2. glucose.

   3. ATP.

   4. ADP.

2. Each gram of glucose contains approximately how much energy?

   1. 1 calorie

   2. 1 Calorie

   3. 4 calories

   4. 4 Calories

3. The process that releases energy from food in the presence of oxygen is

   1. synthesis.

   2. cellular respiration.

   3. ATP synthase.

   4. photosynthesis.

4. The first step in releasing the energy of glucose in the cell is known as

   1. fermentation.

   2. glycolysis.

   3. the Krebs cycle.

   4. electron transport.

5. Which of the following organisms perform cellular respiration?

   

   1. only C

   2. only A and C

   3. only B and D

   4. all of the above

6. What is a calorie? Briefly explain how cells use a high-calorie molecule such as glucose.

7. Write a chemical equation for cellular respiration. Label the molecules involved.

8. What percentage of the energy contained in a molecule of glucose is captured in the bonds of ATP at the end of glycolysis?

9. What does it mean if a process is “anaerobic”? Which part of cellular respiration is anaerobic?

Think Critically

10. Use Analogies Why is comparing cellular respiration to a burning fire a poor analogy?

11. Compare and Contrast Why are cellular respiration and photosynthesis considered opposite reactions?

9.2 The Process of Cellular Respiration

Understand Key Concepts

12. The net gain of energy from glycolysis is

    1. 4 ATP molecules.

    2. 2 ATP molecules.

    3. 8 ADP molecules.

    4. 3 pyruvic acid molecules.

13. The Krebs cycle takes place within the

    1. chloroplast.

    2. nucleus.

    3. mitochondrion.

    4. cytoplasm.

14. The electron transport chain uses the high-energy electrons from the Krebs cycle to

    1. produce glucose.

    2. move H⁺ ions across the inner mitochondrial membrane.

    3. convert acetyl-CoA to citric acid.

    4. convert glucose to pyruvic acid.

15. How is glucose changed during glycolysis?

16. What is NAD⁺? Why is it important?

17. Summarize what happens during the Krebs cycle. What happens to high-energy electrons generated during the Krebs cycle?

18. How is ATP synthase involved in making energy available to the cell?

Think Critically

19. Compare and Contrast How is the function of NAD⁺ in cellular respiration similar to that of NADP⁺ in photosynthesis?

20. Compare and Contrast Where is the electron transport chain found in a eukaryotic cell? Where is it found in a prokaryotic cell?

21. Sequence Explain how the products of glycolysis and the Krebs cycle are related to the electron transport chain. Draw a flowchart that shows the relationships between these products and the electron transport chain.

22. Use Models Draw and label a mitochondrion surrounded by cytoplasm. Indicate where glycolysis, the Krebs cycle, and the electron transport chain occur in a eukaryotic cell.