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

Question 1

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

Accepted Answer

Oxygen ($O_2$)

Question 2

During glycolysis, how many net ATP molecules are produced per molecule of glucose?

Accepted Answer

2 ATP

Question 3

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

Accepted Answer

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

Question 4

A patient’s muscle cells are deprived of oxygen during intense exercise. Which metabolic pathway will their cells primarily use to generate ATP?

Accepted Answer

Lactic acid fermentation

Question 5

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

Accepted Answer

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

Question 6

Which stage of cellular respiration produces the most ATP?

Accepted Answer

Oxidative phosphorylation

Question 7

In the absence of oxygen, yeast cells perform fermentation. What are the main products of alcoholic fermentation?

Accepted Answer

Ethanol, $CO_2$, and ATP

Question 8

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

Accepted Answer

The electron acceptor is called the oxidizing agent.

Question 9

A cell metabolizes one molecule of glucose via aerobic respiration. Approximately how many ATP molecules are produced?

Accepted Answer

32 ATP

Question 10

Which process allows cells to continue producing ATP when oxygen is scarce, by regenerating NAD+ from NADH?

Accepted Answer

Fermentation

Question 11

Which of the following is a key difference between fermentation and cellular respiration?

Accepted Answer

Cellular respiration produces more ATP per glucose molecule than fermentation.

Question 12

During the citric acid cycle, what is the main responsibility of the cycle?

Accepted Answer

To break down acetyl CoA into $CO_2$

Question 13

Which metabolic pathway is responsible for the breakdown of fatty acids into acetyl CoA for entry into the citric acid cycle?

Accepted Answer

Beta oxidation

Question 14

A mutation disables ATP synthase in mitochondria. Which process would be directly affected?

Accepted Answer

Chemiosmosis

Question 15

Which of the following is TRUE about the electron transport chain (ETC) in cellular respiration?

Accepted Answer

The ETC releases energy in a series of small, manageable steps.

Question 16

Which of the following is a similarity between fermentation and cellular respiration?

Accepted Answer

Both use NAD+ as the electron acceptor during glycolysis.

Question 17

A cell is using proteins as an energy source. Which process is required before the products can enter the citric acid cycle?

Accepted Answer

Deamination

Question 18

Which of the following best explains why cellular respiration is considered a highly efficient process compared to fermentation?

Accepted Answer

Cellular respiration produces more ATP per glucose molecule.

Question 19

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

Accepted Answer

Glycolysis → Pyruvate oxidation → Citric acid cycle → Oxidative phosphorylation

Question 20

If a cell is deprived of glucose but has abundant fatty acids, which pathway will allow it to continue producing ATP?

Accepted Answer

Beta oxidation

Cellular Respiration and Fermentation: Key Concepts and Processes

Study Guide - Practice Questions