Question 1

Which molecule is oxidized and which is reduced in the following reaction? $$C_6H_{12}O_6$ + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{Energy}$$

Accepted Answer

Glucose is oxidized; oxygen is reduced.

Question 2

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

Accepted Answer

2 ATP and 2 NADH

Question 3

Which of the following best describes the role of NAD+ in cellular respiration?

Accepted Answer

It acts as an oxidizing agent, accepting electrons during redox reactions.

Question 4

Where in the cell does the citric acid cycle occur?

Accepted Answer

Mitochondrial matrix

Question 5

Which stage of cellular respiration produces the most ATP?

Accepted Answer

Oxidative phosphorylation

Question 6

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

Accepted Answer

To create a proton gradient that drives ATP synthesis

Question 7

Which of the following statements about fermentation is TRUE?

Accepted Answer

Fermentation regenerates NAD+ so glycolysis can continue in the absence of oxygen.

Question 8

Which of the following is a product of the citric acid cycle for each acetyl CoA molecule entering the cycle?

Accepted Answer

3 NADH, 1 FADH2, 1 ATP, and 2 CO2

Question 9

Which process in cellular respiration is considered anaerobic and can occur without oxygen?

Accepted Answer

Glycolysis

Question 10

What is the role of ATP synthase in cellular respiration?

Accepted Answer

It uses the proton gradient to catalyze the conversion of ADP and $$P_i to $$ATP.

Question 11

Which of the following statements about the energy yield of fats compared to carbohydrates is correct?

Accepted Answer

A gram of fat produces more than twice as much ATP as a gram of carbohydrate.

Question 12

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

Accepted Answer

Glucose $$\rightarrow$$ NADH $$\rightarrow$$ Electron Transport Chain $$\rightarrow$$ Oxygen

Question 13

Which of the following best explains why glycolysis is considered one of the most ancient metabolic pathways?

Accepted Answer

It occurs in the cytosol and does not require membrane-bound organelles or oxygen.

Question 14

What is the immediate fate of pyruvate in human muscle cells under anaerobic conditions?

Accepted Answer

It is converted to lactate.

Question 15

Which of the following is a TRUE statement about ATP hydrolysis?

Accepted Answer

ATP hydrolysis releases energy that can be used to drive endergonic reactions.

Question 16

Which of the following is a function of enzymes in cellular respiration?

Accepted Answer

They lower the activation energy required for reactions to proceed.

Question 17

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

A phosphate group is directly transferred from a substrate to ADP, forming ATP.

Question 18

Which of the following is NOT a product of alcohol fermentation?

Accepted Answer

Lactate

Question 19

A patient has a genetic defect that prevents the formation of functional ATP synthase. Which of the following would be the most immediate consequence?

Accepted Answer

The cell would be unable to produce ATP via oxidative phosphorylation.

Cellular Respiration: Mechanisms and Pathways

Study Guide - Practice Questions

Study Guide - Flashcards