Question 1

Which of the following best describes the role of oxygen in aerobic cellular respiration?

Accepted Answer

Oxygen is the final electron acceptor in the electron transport chain, forming water.

Question 2

During the oxidation of glucose in cellular respiration, which molecule is oxidized and which is reduced?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} is $$oxidized and $$\mathrm{O_2$} is $$reduced.

Question 3

Which process in cellular respiration produces the greatest amount of ATP?

Accepted Answer

Oxidative phosphorylation

Question 4

What is the main purpose of the electron transport chain in mitochondria?

Accepted Answer

To pump protons into the intermembrane space, creating a proton gradient used for ATP synthesis

Question 5

Which of the following statements about glycolysis is TRUE?

Accepted Answer

Glycolysis produces a net gain of 2 ATP per glucose molecule by substrate-level phosphorylation.

Question 6

In the absence of oxygen, how do cells regenerate NAD+ to allow glycolysis to continue?

Accepted Answer

By transferring electrons from NADH to pyruvate or its derivatives during fermentation

Question 7

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by the transfer of a phosphate group from a substrate to ADP by an enzyme.

Question 8

Which of the following best explains why the electron transport chain is organized into a series of steps rather than a single reaction?

Accepted Answer

To allow the cell to capture energy in small, manageable amounts for ATP synthesis

Question 9

Which of the following is a product of the citric acid cycle for each acetyl-CoA that enters?

Accepted Answer

1 ATP, 3 NADH, 1 FADH2

Question 10

A patient’s muscle cells are deprived of oxygen. Which process will increase in order to continue producing ATP?

Accepted Answer

Lactic acid fermentation

Question 11

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

Accepted Answer

The substance that is oxidized loses electrons and is called the reducing agent.

Question 12

Which of the following is a difference between alcohol fermentation and lactic acid fermentation?

Accepted Answer

Alcohol fermentation releases $$\mathrm{CO_2$}$$, while lactic acid fermentation does not.

Question 13

Which of the following best describes the fate of pyruvate in aerobic versus anaerobic conditions?

Accepted Answer

In aerobic conditions, pyruvate enters the mitochondria for complete oxidation; in anaerobic conditions, it is reduced to lactate or ethanol.

Question 14

Which of the following is a real-world example of an organism using an alternative final electron acceptor in anaerobic respiration?

Accepted Answer

A bacterium using sulfate ($$\mathrm{SO_4$^{2-}}) as a $$final electron acceptor, producing hydrogen sulfide ($$\mathrm{H_2S})$$

Question 15

Which of the following best explains why obligate anaerobes cannot survive in the presence of oxygen?

Accepted Answer

Oxygen is toxic to obligate anaerobes because they lack enzymes to detoxify reactive oxygen species.

Question 16

A mutation disables the enzyme ATP synthase in a eukaryotic cell. Which process will be most directly affected?

Accepted Answer

Oxidative phosphorylation during chemiosmosis

Question 17

Which of the following equations correctly represents the overall reaction for aerobic cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} ightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + 	ext{Energy}$$

Question 18

Which of the following best describes the function of NAD+ in cellular respiration?

Accepted Answer

NAD+ acts as an electron carrier, accepting electrons during redox reactions.

Cellular Respiration: Catabolic Pathways and ATP Production

Study Guide - Practice Questions