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

Question 1

Which of the following statements best describes the role of cellular respiration in heterotrophs?

Accepted Answer

Cellular respiration enables heterotrophs to extract energy from organic molecules obtained from other organisms.

Question 2

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

Accepted Answer

Net gain of 2 ATP and 2 NADH

Question 3

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

Accepted Answer

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

Question 4

What is the final electron acceptor in aerobic respiration?

Accepted Answer

Oxygen ($$O_2)$$

Question 5

Which process directly produces ATP by substrate-level phosphorylation?

Accepted Answer

Glycolysis

Question 6

In the absence of oxygen, what happens to pyruvate in human muscle cells?

Accepted Answer

It is reduced to lactate during fermentation.

Question 7

Which of the following best explains why cellular respiration occurs in multiple steps rather than all at once?

Accepted Answer

To release energy in small, manageable amounts and efficiently capture it as ATP.

Question 8

Which molecule is produced when pyruvate is oxidized in the presence of oxygen?

Accepted Answer

Acetyl-CoA

Question 9

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

Accepted Answer

To transfer electrons and create a proton gradient for ATP synthesis.

Question 10

Which of the following is a correct description of autotrophs?

Accepted Answer

Autotrophs produce their own organic molecules through photosynthesis.

Question 11

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

Accepted Answer

Electrons are transferred from high-energy molecules to low-energy acceptors.

Question 12

During oxidative phosphorylation, ATP synthase uses energy from which source?

Accepted Answer

A proton gradient across the mitochondrial membrane

Question 13

Which of the following is NOT a product of glycolysis?

Accepted Answer

Acetyl-CoA

Question 14

A patient is unable to efficiently produce ATP through oxidative phosphorylation. Which part of cellular respiration is most likely affected?

Accepted Answer

Electron Transport Chain

Question 15

Which equation correctly represents the overall reaction of aerobic cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{energy}$$

Question 16

Which of the following statements about ATP is correct?

Accepted Answer

ATP is unstable and must be used as soon as it is created.

Question 17

In prokaryotes, where does pyruvate oxidation occur?

Accepted Answer

At the plasma membrane

Question 18

Which of the following is a consequence of blocking NAD+ regeneration during fermentation?

Accepted Answer

Glycolysis would stop due to lack of NAD+.

Question 19

A mutation disables pyruvate dehydrogenase in a eukaryotic cell. Which process would be directly affected?

Accepted Answer

Conversion of pyruvate to acetyl-CoA

Question 20

Which of the following is true regarding the energy transfer in cellular respiration?

Accepted Answer

Energy from glucose is transferred to ATP through a series of redox reactions.

Cellular Respiration: Overview, Glycolysis, and Pyruvate Oxidation

Study Guide - Practice Questions