Question 1

Which of the following best describes the role of an enzyme in a biochemical reaction?

Accepted Answer

Enzymes lower the activation energy, allowing reactions to proceed more rapidly.

Question 2

Which of the following is TRUE regarding substrate-level phosphorylation?

Accepted Answer

It is the main method of ATP production during fermentation.

Question 3

A competitive inhibitor of an enzyme acts by:

Accepted Answer

Binding to the active site, preventing substrate binding.

Question 4

Which molecule is reduced during the following reaction: $$ \mathrm{NAD}^+ + 2e^- + 2H^+ \rightarrow \mathrm{NADH} + H^+ $$?

Accepted Answer

$$\mathrm{NAD}^+$$

Question 5

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

Accepted Answer

Pyruvate

Question 6

In aerobic respiration, what is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen ($$\mathrm{O}_2)$$

Question 7

Which of the following statements about fermentation is CORRECT?

Accepted Answer

Fermentation uses an organic molecule as the final electron acceptor.

Question 8

Which of the following best describes the function of cytochrome c in cellular respiration?

Accepted Answer

It is an electron carrier in the electron transport chain.

Question 9

Which of the following conditions would most likely cause an enzyme to denature?

Accepted Answer

A large change in pH.

Question 10

Which of the following is a correct summary of ATP yield from one molecule of glucose in prokaryotic aerobic respiration?

Accepted Answer

$$38$$ ATP

Question 11

Which of the following is a function of proteins in cells?

Accepted Answer

Catalyzing chemical reactions

Question 12

Which of the following statements about the electron transport chain (ETC) is FALSE?

Accepted Answer

The ETC directly produces ATP without the need for ATP synthase.

Question 13

Which of the following best explains why fermentation is less efficient than aerobic respiration?

Accepted Answer

Fermentation does not fully oxidize glucose to CO$$_2$$ and H$$_2O.$$

Question 14

Which of the following is an example of an inorganic cofactor required by some enzymes?

Accepted Answer

Mg$$^{2+}$$

Question 15

Which process is responsible for the conversion of pyruvate to acetyl-CoA?

Accepted Answer

Pyruvate dehydrogenase complex

Question 16

Which of the following statements about anabolic reactions is TRUE?

Accepted Answer

They use precursor metabolites, ATP, and enzymes to build macromolecules.

Question 17

Which of the following is a correct pairing of an electron carrier and its reduced form?

Accepted Answer

NAD$$^+$$ and NADH

Question 18

Which of the following best describes the term 'holoenzyme'?

Accepted Answer

An enzyme with its cofactor bound

Question 19

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactic acid

Question 20

Which statement best explains why cells regulate the expression of catabolic enzymes?

Accepted Answer

To conserve energy by producing enzymes only when their substrate is available.

Microbial Metabolism: Enzymes, Catabolism, and Energy Production

Study Guide - Practice Questions