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 substrate-level phosphorylation, how is ATP generated?

Accepted Answer

An enzyme directly transfers a phosphate group from a substrate to ADP.

Question 3

Which equation correctly summarizes aerobic cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$$

Question 4

Which process in cellular respiration produces the most ATP?

Accepted Answer

Oxidative phosphorylation (electron transport chain and chemiosmosis)

Question 5

What is the main function of NAD+ in cellular respiration?

Accepted Answer

To carry electrons from one reaction to another, becoming reduced to NADH

Question 6

Which of the following is a correct sequence of events in aerobic cellular respiration?

Accepted Answer

Glycolysis → Pyruvate oxidation → Citric Acid Cycle → Electron Transport Chain

Question 7

In the absence of oxygen, which process allows cells to continue producing ATP?

Accepted Answer

Fermentation

Question 8

Which of the following statements about chemiosmosis is correct?

Accepted Answer

Chemiosmosis uses a proton gradient to power ATP synthesis via ATP synthase.

Question 9

Which molecule is oxidized during glycolysis?

Accepted Answer

Glucose

Question 10

A muscle cell is deprived of oxygen but must continue to function. Which pathway will it use to generate ATP?

Accepted Answer

Lactic acid fermentation

Question 11

Which of the following is a product of the citric acid cycle (Krebs cycle)?

Accepted Answer

NADH

Question 12

What is the main difference between aerobic and anaerobic cellular respiration?

Accepted Answer

Aerobic respiration uses oxygen as the final electron acceptor, while anaerobic uses other molecules.

Question 13

Which of the following best explains why anaerobic respiration is less efficient than aerobic respiration?

Accepted Answer

Anaerobic respiration produces less ATP because the electron transport chain is not used.

Question 14

Which process directly produces ATP by transferring a phosphate group from a high-energy substrate to ADP?

Accepted Answer

Substrate-level phosphorylation

Question 15

Which of the following is a correct description of a redox reaction in cellular respiration?

Accepted Answer

The loss of hydrogen atoms from a molecule is oxidation.

Question 16

Which molecule acts as the final electron acceptor in the electron transport chain during aerobic respiration?

Accepted Answer

Oxygen ($$O_2)$$

Question 17

A facultative anaerobic organism is placed in an environment with no oxygen. What will happen?

Accepted Answer

It will switch to anaerobic respiration or fermentation to generate ATP.

Question 18

Which of the following is NOT a product of glycolysis?

Accepted Answer

Oxygen

Question 19

Which process in cellular respiration is responsible for creating a proton gradient across the inner mitochondrial membrane?

Accepted Answer

Electron transport chain

Question 20

If a cell's mitochondria are damaged and cannot function, which process can still produce ATP?

Accepted Answer

Glycolysis

Cellular Respiration and Energy Harvesting in Cells

Study Guide - Practice Questions