$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 \rightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2\mathrm{O} + \text{Energy (ATP + heat)}$$

Question 1

Which of the following best represents the overall equation for cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 ightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2\mathrm{O} + 	ext{Energy (ATP + heat)}$$

Question 2

Where does glycolysis occur in eukaryotic cells?

Accepted Answer

In the cytoplasm

Question 3

Which process produces the most ATP during cellular respiration?

Accepted Answer

Oxidative phosphorylation

Question 4

What is substrate-level phosphorylation?

Accepted Answer

The direct transfer of a phosphate group from an organic substrate to ADP by an enzyme

Question 5

During the oxidation of glucose, which molecule acts as the final electron acceptor in aerobic respiration?

Accepted Answer

O$$_2$$

Question 6

Which of the following statements about redox reactions in cellular respiration is correct?

Accepted Answer

Glucose is oxidized and oxygen is reduced.

Question 7

What is the main function of the electron transport chain in cellular respiration?

Accepted Answer

To transfer electrons from NADH and FADH$$_2 to $$oxygen, creating a proton gradient

Question 8

Which of the following best describes the role of cytochromes in the electron transport chain?

Accepted Answer

They are proteins that transfer electrons between complexes in the electron transport chain.

Question 9

A patient is diagnosed with a mitochondrial disorder that impairs the function of ATP synthase. Which process would be most directly affected?

Accepted Answer

Oxidative phosphorylation

Question 10

Which of the following is a key difference between fermentation and aerobic respiration?

Accepted Answer

Fermentation uses an organic molecule as the final electron acceptor, while aerobic respiration uses oxygen.

Question 11

In lactic acid fermentation, which molecule is reduced to form lactate?

Accepted Answer

Pyruvate

Question 12

Which of the following best explains why fats produce more ATP per gram than carbohydrates?

Accepted Answer

Fats are more reduced and thus have more high-energy electrons to donate to NAD+ and FAD.

Question 13

Which of the following is NOT a product of the citric acid cycle for each turn of the cycle?

Accepted Answer

2 FADH$$_2$$

Question 14

A researcher adds a chemical that makes the inner mitochondrial membrane permeable to protons. What is the most likely effect on ATP synthesis?

Accepted Answer

ATP synthesis would decrease because the proton gradient would be dissipated.

Question 15

Which of the following statements about glycolysis is true?

Accepted Answer

Glycolysis produces a net gain of 2 ATP per glucose molecule.

Question 16

Which of the following best describes the fate of pyruvate in the presence of oxygen in eukaryotic cells?

Accepted Answer

It enters the mitochondrion and is converted to acetyl CoA.

Question 17

Which of the following is a correct sequence of energy flow during cellular respiration?

Accepted Answer

Glucose $$\rightarrow$$ NADH $$\rightarrow$$ Electron transport chain $$\rightarrow$$ Proton-motive force $$\rightarrow$$ ATP

Question 18

Which of the following is a function of feedback inhibition in cellular respiration?

Accepted Answer

To prevent the wasteful overproduction of ATP

Question 19

A facultative anaerobe is grown in a sealed container with no oxygen. Which pathway will it use to generate ATP?

Accepted Answer

Fermentation

Question 20

Which of the following statements about the evolutionary significance of glycolysis is correct?

Accepted Answer

Glycolysis is found in nearly all organisms, suggesting it is an ancient metabolic pathway.

Cellular Respiration and Fermentation: Energy Harvesting in Cells

Study Guide - Practice Questions