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

Question 1

Which of the following best describes an amphibolic pathway in microbial metabolism?

Accepted Answer

A pathway that can function in both catabolic and anabolic processes.

Question 2

During glycolysis, glucose is converted into pyruvic acid. What is the net ATP yield from this process per molecule of glucose?

Accepted Answer

2 ATP

Question 3

Which of the following statements about enzymes is TRUE?

Accepted Answer

Enzymes lower the activation energy, speeding up reactions.

Question 4

A patient’s cells are unable to regenerate NAD⁺ due to a defective electron transport chain. Which metabolic pathway will be most affected?

Accepted Answer

Glycolysis

Question 5

Which of the following is the correct overall equation for aerobic cellular respiration?

Accepted Answer

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

Question 6

Which process directly transfers a phosphate group to ADP to form ATP?

Accepted Answer

Substrate-level phosphorylation

Question 7

In feedback inhibition, what is the role of the end product?

Accepted Answer

It inhibits an early enzyme in the pathway to regulate activity.

Question 8

Which of the following is NOT a final electron acceptor in anaerobic respiration?

Accepted Answer

$$O_2$$

Question 9

A microorganism is growing in an environment without oxygen and produces lactic acid as a metabolic end product. Which pathway is it using?

Accepted Answer

Fermentation

Question 10

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

Accepted Answer

It shuttles electrons during redox reactions, becoming NADH.

Question 11

Which step in cellular respiration produces the most ATP?

Accepted Answer

Electron transport chain (ETC) and chemiosmosis

Question 12

A bacterial cell is exposed to a competitive inhibitor. What is the most likely effect on its enzyme activity?

Accepted Answer

The inhibitor binds to the active site, preventing substrate binding.

Question 13

Which of the following is TRUE about fermentation?

Accepted Answer

It regenerates NAD⁺ so glycolysis can continue.

Question 14

Which of the following is an example of an anabolic pathway?

Accepted Answer

Protein synthesis from amino acids

Question 15

A cell is placed in an environment with a pH far outside its optimal range. What is the most likely effect on its enzymes?

Accepted Answer

Enzyme activity will decrease due to denaturation.

Question 16

Which of the following statements about ATP is correct?

Accepted Answer

ATP stores energy in its phosphate bonds.

Question 17

Which of the following is a cofactor that may be required for enzyme activity?

Accepted Answer

Iron ion ($$Fe^{2+})$$

Question 18

In oxidative phosphorylation, what is the main mechanism by which ATP is produced?

Accepted Answer

ATP synthase uses a proton gradient generated by the electron transport chain

Question 19

Which of the following best describes a redox reaction?

Accepted Answer

A reaction where electrons are transferred from one molecule to another.

Question 20

A cell is exposed to a noncompetitive inhibitor. What is the most likely effect?

Accepted Answer

The inhibitor binds to an allosteric site, changing enzyme shape and reducing activity.

Microbial Metabolism: Study Guide and Key Concepts

Study Guide - Practice Questions