Understanding Cellular Respiration

Cellular respiration is a process that all living things use to convert glucose into energy. Let’s see how well you understand this process!

Practice Questions

Which of the following shows the correct order of cellular respiration?

  1. glycolysis, pyruvate oxidation, the citric acid cycle, and the electron transport chain
  2. glycolysis, pyruvate oxidation, the electron transport chain, and the citric acid cycle
  3. pyruvate oxidation, glycolysis, the citric acid cycle, and the electron transport chain

Which of the pathway(s) in cellular respiration are aerobic?

  1. glycolysis
  2. the citric acid cycle
  3. the electron transport chain

Which is an accurate description of glycolysis?

  1. This pathway breaks down glucose to produce 2 pyruvate molecules. It has two halves: the energy-requiring steps and the energy-releasing steps. The first half consumes 2 ATP, and the second half produces 4 ATP and 2 NADH, giving a net gain of 2 ATP and 2 NADH.
  2. This pathway is a closed loop composed of eight steps: the final step produces the compound needed for the first step. Each round of this pathway produces 3 NADH and 1 FADH2.
  3. This pathway produces 90 percent of the ATP generated during cellular respiration. A proton pump spins a “motor”; this movement converts ADP to ATP.

What happens if there is no oxygen present after glycolysis is completed?

However, if there is oxygen available, cellular respiration will continue to the next step: pyruvate oxidation. In pyruvate oxidation, what is pyruvate converted into?

  1. carboxyl groups
  2. coenzyme A
  3. acetyl CoA

The next pathway in cellular respiration is the citric acid cycle. How does ATP concentration affect the rate of the citric acid cycle? Why?

What is the net energy gain of the citric acid cycle?

  1. 2 ATP and 2 NADH
  2. 3 NADH and 1 FADH2
  3. 90 percent of a cell’s ATP

What is true of the electron transport chain?

  1. It is the only aerobic pathway in cellular respiration.
  2. It is the only pathway in cellular respiration that directly consumes oxygen.
  3. It is the only pathway in cellular respiration that involves the oxidation of compounds.