Question 1

Which of the following best describes the difference between catabolism and anabolism in microbial metabolism?

Accepted Answer

Catabolism is the energy-releasing breakdown of molecules, while anabolism is the energy-consuming synthesis of cellular material.

Question 2

A microorganism that uses light as an energy source and CO$_2$ as a carbon source is classified as a:

Accepted Answer

Photoautotroph

Question 3

Which of the following statements about enzymes is CORRECT?

Accepted Answer

Enzymes lower the activation energy barrier, increasing the reaction rate without being consumed.

Question 4

Which of the following is a characteristic of a prosthetic group in an enzyme?

Accepted Answer

It is tightly bound, often covalently, and remains permanently attached to the enzyme.

Question 5

In glycolysis, ATP is produced by which mechanism?

Accepted Answer

Substrate-level phosphorylation

Question 6

Which of the following best explains why fermentation yields less energy than aerobic respiration?

Accepted Answer

Fermentation does not use an electron transport chain and only partially oxidizes glucose.

Question 7

Which of the following is the final electron acceptor in aerobic respiration?

Accepted Answer

Oxygen (O$_2$)

Question 8

A bacterium that oxidizes H$_2$S for energy and uses CO$_2$ as a carbon source is best classified as a:

Accepted Answer

Chemolithoautotroph

Question 9

Which of the following statements about the electron transport chain (ETC) in prokaryotes is TRUE?

Accepted Answer

The ETC is located in the cytoplasmic membrane and generates a proton motive force.

Question 10

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

Accepted Answer

ATP is generated by the transfer of a phosphate group from a high-energy substrate directly to ADP.

Question 11

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

Accepted Answer

O$_2$

Question 12

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

Accepted Answer

It is a coenzyme that shuttles electrons from catabolic reactions to the electron transport chain.

Question 13

Which of the following is a key difference between the lipids of Bacteria/Eukarya and Archaea?

Accepted Answer

Bacteria and Eukarya use fatty acids, while Archaea use phytanyl side chains.

Question 14

A microorganism is found to store energy in the form of poly-β-hydroxybutyrate. This is an example of:

Accepted Answer

Long-term energy storage in prokaryotes

Question 15

Which of the following best explains why high temperatures can inhibit enzyme activity?

Accepted Answer

High temperatures denature the enzyme, altering the shape of the active site.

Question 16

Which of the following is a product of fermentation in yeast that is important in the food and beverage industry?

Accepted Answer

Ethanol

Question 17

Which of the following statements about chemolithotrophy is TRUE?

Accepted Answer

Chemolithotrophs use inorganic compounds as electron donors and are often autotrophic.

Question 18

Which of the following is a correct equation for the reduction of NAD$^+$ to NADH?

Accepted Answer

$$\mathrm{NAD^+ + H^+ + 2e^- \rightarrow NADH}$$

Question 19

Which of the following is a direct result of the proton motive force generated by the electron transport chain?

Accepted Answer

Synthesis of ATP by ATP synthase

Microbial Metabolism: Energy, Enzymes, and Pathways

Study Guide - Practice Questions