Question 1

Which of the following best describes the difference between a linear and a cyclic metabolic pathway?

Accepted Answer

A linear pathway has a distinct start and end, while a cyclic pathway regenerates its starting molecule and repeats.

Question 2

Which of the following is an example of a catabolic pathway?

Accepted Answer

Breakdown of glucose into water, carbon dioxide, and energy

Question 3

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

Accepted Answer

$$2$$

Question 4

Which coenzyme is responsible for picking up hydrogen ions and electrons during glycolysis?

Accepted Answer

NAD+

Question 5

What is the primary immediate source of energy for cellular activities?

Accepted Answer

ATP

Question 6

Which of the following best describes the role of enzymes in metabolic pathways?

Accepted Answer

They lower the activation energy and are reused in multiple reactions.

Question 7

What happens to pyruvate molecules produced during glycolysis if oxygen is NOT present?

Accepted Answer

No further ATP is produced from them via aerobic respiration.

Question 8

Which step of cellular respiration does NOT produce ATP directly?

Accepted Answer

Preparatory step

Question 9

What is the correct sequence of steps in cellular respiration?

Accepted Answer

Glycolysis → Preparatory step → Citric acid cycle → Electron transport system

Question 10

Which of the following statements about ATP is TRUE?

Accepted Answer

ATP stores energy in the bonds between its phosphate groups.

Question 11

During the preparatory step of cellular respiration, what is the fate of the carbon atoms from pyruvate?

Accepted Answer

They are released as carbon dioxide.

Question 12

Which molecule acts as a carrier for the acetyl group into the citric acid cycle?

Accepted Answer

Coenzyme A

Question 13

If a cell is deprived of glucose, which macromolecule will it most likely use next for ATP production?

Accepted Answer

Lipids

Question 14

Which of the following best explains why NAD+ is important in cellular respiration?

Accepted Answer

It accepts electrons and hydrogen ions during glycolysis and the preparatory step.

Question 15

How many NADH molecules are produced per glucose molecule during glycolysis?

Accepted Answer

$$2$$

Question 16

Which of the following is a waste product of the preparatory step in cellular respiration?

Accepted Answer

Carbon dioxide

Question 17

Which process occurs in the cytoplasm of the cell?

Accepted Answer

Glycolysis

Question 18

What is the main function of coenzymes such as NAD+ and FAD in metabolism?

Accepted Answer

To transfer electrons and hydrogen ions during metabolic reactions

Question 19

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

The direct transfer of a phosphate group to ADP from a substrate molecule

Question 20

A patient has a genetic defect that prevents the formation of coenzyme A. Which step of cellular respiration would be directly affected?

Accepted Answer

Preparatory step

Metabolic Pathways and Cellular Respiration: Introduction to Energy Production

Study Guide - Practice Questions