Question 1

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

Accepted Answer

A pathway that can function in both catabolism and anabolism, depending on cellular needs.

Question 2

Which equation correctly represents the overall reaction for aerobic cellular respiration in prokaryotes?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} + 38\mathrm{ADP} + 38\mathrm{PO_4$^{3-}} \rightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + 38\mathrm{ATP}$$

Question 3

Which of the following statements about ATP is TRUE?

Accepted Answer

ATP is generated on demand and cannot be effectively stored by cells.

Question 4

A cell is exposed to a temperature above the optimal for its enzymes. What is the most likely outcome?

Accepted Answer

Enzyme activity will decrease due to denaturation.

Question 5

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

Accepted Answer

The breakdown of glucose into carbon dioxide and water.

Question 6

Which enzyme class is responsible for transferring functional groups from one molecule to another?

Accepted Answer

Transferase

Question 7

What is the role of NAD+ in cellular metabolism?

Accepted Answer

It serves as an electron carrier in catabolic reactions.

Question 8

Which of the following best explains why cells favor ATP ⇄ ADP cycling?

Accepted Answer

It is more energy-efficient, faster, and easier to regulate than storing ATP.

Question 9

Which of the following is NOT a characteristic of enzymes?

Accepted Answer

They are consumed during the reaction.

Question 10

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Competing with the substrate for the enzyme's active site.

Question 11

Which phosphorylation mechanism is used in glycolysis to recharge ADP to ATP?

Accepted Answer

Substrate-level phosphorylation

Question 12

Which of the following is TRUE regarding fermentation?

Accepted Answer

Fermentation is less efficient than aerobic respiration, typically yielding 2–3 ATP per glucose.

Question 13

Which of the following is a final electron acceptor in anaerobic respiration for nitrogen-fixing bacteria?

Accepted Answer

Nitrate ($$\mathrm{NO_3$^-})$$

Question 14

Which statement best describes the effect of pH on enzyme activity?

Accepted Answer

Extreme changes in pH can disrupt hydrogen and ionic bonds, leading to enzyme denaturation.

Question 15

Which of the following is a TRUE statement about the electron transport chain in eukaryotic cells?

Accepted Answer

It is located in the inner mitochondrial membrane.

Question 16

Which of the following is NOT a product of the Krebs cycle?

Accepted Answer

Glucose

Question 17

Which of the following best describes the role of ATP synthase in chemiosmosis?

Accepted Answer

It allows protons to flow back across the membrane, synthesizing ATP from ADP and inorganic phosphate.

Question 18

Which of the following is a reason why diabetics are at risk for wound infections by anaerobic bacteria like Clostridium perfringens?

Accepted Answer

Poor circulation and tissue hypoxia create an environment favorable for anaerobic growth.

Question 19

Which biochemical test would most likely be negative for Clostridium perfringens, and why?

Accepted Answer

Oxidase test, because C. perfringens lacks cytochrome c oxidase.

CH. 8 Microbial Metabolism: Principles, Pathways, and Clinical Applications

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