$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP + heat)}$$

Question 1

Which of the following best describes the overall chemical equation for aerobic cellular respiration using glucose as the substrate?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{Energy (ATP + heat)}$$

Question 2

During cellular respiration, which molecule is oxidized and which is reduced?

Accepted Answer

Glucose is oxidized; oxygen is reduced.

Question 3

Which stage of cellular respiration produces the most ATP?

Accepted Answer

Oxidative phosphorylation

Question 4

What is the role of NAD$$^+ in $$cellular respiration?

Accepted Answer

It functions as an electron carrier, accepting electrons during redox reactions.

Question 5

Which process directly produces ATP by substrate-level phosphorylation?

Accepted Answer

Glycolysis and the citric acid cycle

Question 6

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

Accepted Answer

Fermentation

Question 7

Which of the following is a product of the transition reaction (pyruvate oxidation) before the citric acid cycle?

Accepted Answer

Acetyl CoA

Question 8

During the citric acid cycle, how many NADH molecules are produced per turn of the cycle?

Accepted Answer

3

Question 9

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

Accepted Answer

O$$_2$$

Question 10

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

Accepted Answer

To generate a proton gradient for ATP synthesis

Question 11

Which of the following statements about chemiosmosis is correct?

Accepted Answer

It uses the energy of a proton gradient to drive ATP synthesis.

Question 12

Which type of fermentation occurs in human muscle cells under anaerobic conditions?

Accepted Answer

Lactic acid fermentation

Question 13

Fatty acids are broken down by beta oxidation. What is the main product that enters cellular respiration from this process?

Accepted Answer

Acetyl CoA

Question 14

Which of the following statements best explains why fats produce more ATP per gram than carbohydrates?

Accepted Answer

Fats have more electrons available for transfer in redox reactions.

Question 15

A patient is unable to use oxygen efficiently in their cells. Which stage of cellular respiration would be most directly affected?

Accepted Answer

Oxidative phosphorylation

Question 16

Which enzyme catalyzes the first step of glycolysis, converting glucose to glucose-6-phosphate?

Accepted Answer

Hexokinase

Question 17

If a cell is deprived of NAD$$^+$$, which process would be most immediately inhibited?

Accepted Answer

Glycolysis

Question 18

Which of the following is NOT a direct product of glycolysis?

Accepted Answer

CO$$_2$$

Question 19

Which of the following pathways can proteins enter after deamination?

Accepted Answer

Either glycolysis or the citric acid cycle, depending on the amino acid

Question 20

A yeast cell is growing in an environment without oxygen. Which metabolic pathway will it use to generate ATP?

Accepted Answer

Alcohol fermentation

Cellular Respiration: Mechanisms and Pathways

Study Guide - Practice Questions