Question 1

Which of the following best describes an exergonic reaction in microbial metabolism?

Accepted Answer

A reaction that releases energy during the process

Question 2

During a redox reaction in a bacterial cell, which of the following statements is correct?

Accepted Answer

The electron acceptor is reduced

Question 3

Which of the following correctly represents the reduction of NAD+ during cellular respiration?

Accepted Answer

$$\mathrm{NAD}^+ \rightarrow \mathrm{NADH}$$

Question 4

Which property of ATP makes it especially suitable as the primary energy currency in cells?

Accepted Answer

It can accumulate to high concentrations without harming the cell

Question 5

Which of the following is NOT a method by which ATP can be generated in cells?

Accepted Answer

Direct absorption of ATP from the environment

Question 6

Apoenzymes require which of the following to become functional holoenzymes?

Accepted Answer

A cofactor, which may be an inorganic ion or an organic coenzyme

Question 7

Which enzyme class is responsible for catalyzing the rearrangement of atoms within a molecule?

Accepted Answer

Isomerases

Question 8

A patient is given sulfanilamide to treat a bacterial infection. This drug works by:

Accepted Answer

Filling the active site of an enzyme needed for folic acid synthesis, acting as a competitive inhibitor

Question 9

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway inhibits an enzyme earlier in the pathway

Question 10

During glycolysis, the oxidation of two molecules of glyceraldehyde-3-phosphate (G3P) results in the formation of:

Accepted Answer

Two molecules of pyruvic acid

Question 11

In the conversion of pyruvic acid to acetyl-CoA, how many molecules of carbon dioxide are released per molecule of glucose?

Accepted Answer

Two

Question 12

Which of the following statements about the Krebs cycle is TRUE?

Accepted Answer

It is also used for the catabolism of lipids and proteins

Question 13

Which component of the electron transport chain is a lipid-soluble, nonprotein carrier derived from vitamin K?

Accepted Answer

Ubiquinones

Question 14

What is the main function of the proton gradient generated during cellular respiration?

Accepted Answer

To generate ATP via chemiosmosis

Question 15

Which pathway is an alternative to glycolysis for the breakdown of glucose and is found only in prokaryotes?

Accepted Answer

Entner-Doudoroff (ED) pathway

Question 16

Which of the following best describes fermentation in microbial metabolism?

Accepted Answer

Partial oxidation of sugar to release energy using an organic molecule as the final electron acceptor

Question 17

A scientist observes that an enzyme's activity decreases sharply when the temperature is raised above 60°C. What is the most likely explanation?

Accepted Answer

The enzyme is denatured due to the breakage of noncovalent bonds

Question 18

Which of the following is an example of a transferase enzyme reaction?

Accepted Answer

Transferring a phosphate group from ATP to glucose

Question 19

A mutation causes an enzyme to lose its allosteric site. Which of the following is a likely consequence?

Accepted Answer

The enzyme cannot be regulated by molecules that bind outside the active site

Question 20

Which of the following statements about enzyme-substrate interactions is correct according to the induced fit model?

Accepted Answer

The active site changes shape to better fit the substrate upon binding

Microbial Metabolism: Enzymes, Energy, and Pathways

Study Guide - Practice Questions