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

Glucose ($$\text{C}_6\text{H}_{12}\text{O}_6)$$

Question 1

Which of the following best describes the overall chemical equation for aerobic cellular respiration?

Accepted Answer

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

Question 2

During which stage of cellular respiration is the majority of ATP produced?

Accepted Answer

Electron transport and oxidative phosphorylation

Question 3

Which molecule is oxidized during cellular respiration?

Accepted Answer

Glucose ($$	ext{C}_6	ext{H}_{12}	ext{O}_6)$$

Question 4

What is the primary function of the electron transport chain in mitochondria?

Accepted Answer

To pump protons across the inner mitochondrial membrane, creating a proton gradient

Question 5

Which enzyme is allosterically inhibited by ATP during glycolysis, thus regulating the pathway?

Accepted Answer

Phosphofructokinase

Question 6

A patient’s muscle cells are deprived of oxygen during intense exercise. Which metabolic pathway will their cells rely on to continue producing ATP?

Accepted Answer

Lactic acid fermentation

Question 7

Which of the following is NOT a product of the citric acid cycle per turn (one acetyl CoA)?

Accepted Answer

Glucose

Question 8

Why is oxygen considered the most effective terminal electron acceptor in aerobic respiration?

Accepted Answer

It allows for the greatest ATP yield due to its high electronegativity

Question 9

Which of the following statements about fermentation is FALSE?

Accepted Answer

NADH donates electrons to the electron transport chain during fermentation

Question 10

In the absence of oxygen, what is the main purpose of fermentation in cells?

Accepted Answer

To regenerate NAD+ so glycolysis can continue

Question 11

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

Accepted Answer

Glycolysis → Pyruvate processing → Citric acid cycle → Electron transport chain

Question 12

A soil bacterium uses nitrate ($$	ext{NO}_3^-) as $$its terminal electron acceptor instead of oxygen. This process is best described as:

Accepted Answer

Anaerobic respiration

Question 13

Which of the following best explains why fats yield more ATP per gram than carbohydrates during cellular respiration?

Accepted Answer

Fats have more high-energy C-H bonds, providing more electrons for the electron transport chain

Question 14

Which of the following is regenerated at the end of the citric acid cycle, allowing the cycle to continue?

Accepted Answer

Oxaloacetate

Question 15

If a mutation caused ATP synthase to become nonfunctional, what would be the most immediate effect on the cell?

Accepted Answer

The cell would be unable to produce ATP via oxidative phosphorylation

Question 16

Which of the following is a direct result of the proton gradient established by the electron transport chain?

Accepted Answer

Production of ATP by ATP synthase

Question 17

Which process is responsible for the net production of 2 ATP and 2 NADH per glucose molecule in the cytosol?

Accepted Answer

Glycolysis

Question 18

A person is fasting and their cells begin to use proteins for energy. Which pathway will the amino acids most likely enter?

Accepted Answer

Glycolysis or the citric acid cycle, depending on the amino acid

Question 19

Which of the following statements about facultative anaerobes is correct?

Accepted Answer

They can switch between aerobic respiration and fermentation depending on oxygen availability

Question 20

Which of the following is a real-world consequence of methanogen bacteria using $$	ext{CO}_2 as a $$terminal electron acceptor?

Accepted Answer

Release of methane, a greenhouse gas, into the atmosphere

Cellular Respiration and Fermentation: Mechanisms of Energy Harvest in Cells

Study Guide - Practice Questions