Question 1

Which of the following best describes the overall chemical reaction for cellular respiration, and which molecule is oxidized?

Accepted Answer

$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \ \mathrm{O}_2 \rightarrow 6 \ \mathrm{CO}_2 + 6 \ \mathrm{H}_2O$; glucose is oxidized

Question 2

During glycolysis, what is the net gain of ATP and NADH per molecule of glucose?

Accepted Answer

2 ATP and 2 NADH

Question 3

Which of the following statements about NAD+ is correct?

Accepted Answer

NAD+ is reduced to NADH during glycolysis and the citric acid cycle

Question 4

Where does the citric acid cycle take place in eukaryotic cells?

Accepted Answer

In the mitochondrial matrix

Question 5

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

Accepted Answer

To transfer electrons from NADH and FADH2 to oxygen, creating a proton gradient

Question 6

Which of the following best explains why oxygen is required for aerobic respiration?

Accepted Answer

Oxygen acts as the final electron acceptor in the electron transport chain

Question 7

In the absence of oxygen, which process allows glycolysis to continue by regenerating NAD+?

Accepted Answer

Fermentation

Question 8

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactate

Question 9

What is the first step of the citric acid cycle?

Accepted Answer

Acetyl-CoA combines with oxaloacetate to form citrate

Question 10

How many turns of the citric acid cycle occur for each molecule of glucose that enters cellular respiration?

Accepted Answer

Two

Question 11

Which of the following best describes chemiosmosis in mitochondria?

Accepted Answer

The movement of H+ ions down their gradient through ATP synthase to generate ATP

Question 12

Which of the following is NOT a product of the complete aerobic breakdown of one molecule of glucose?

Accepted Answer

Lactate

Question 13

Which of the following macromolecules yields the most ATP per gram when oxidized in cellular respiration?

Accepted Answer

Fats

Question 14

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

Accepted Answer

Chemiosmosis

Question 15

Which of the following statements about feedback inhibition in cellular respiration is correct?

Accepted Answer

High levels of ATP inhibit key enzymes in glycolysis

Question 16

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

Accepted Answer

Glucose $\rightarrow$ NADH $\rightarrow$ electron transport chain $\rightarrow$ proton-motive force $\rightarrow$ ATP

Question 17

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 18

A facultative anaerobe is placed in an environment with no oxygen. Which pathway will it use to generate ATP?

Accepted Answer

Fermentation

Question 19

Which of the following is true regarding substrate-level phosphorylation?

Accepted Answer

It occurs during glycolysis and the citric acid cycle

Question 20

If a cell is using fatty acids as an energy source, which molecule will they be converted into before entering the citric acid cycle?

Accepted Answer

Acetyl-CoA

Cellular Respiration and Fermentation: Mechanisms, Pathways, and Regulation

Study Guide - Practice Questions