$$\text{Substrate-P} + \mathrm{ADP} \rightarrow \text{Substrate} + \mathrm{ATP}$$

Question 1

Which of the following best describes the ultimate function of metabolism in a microbial cell?

Accepted Answer

To reproduce the organism

Question 2

Which statement correctly distinguishes catabolic and anabolic pathways?

Accepted Answer

Catabolic pathways are exergonic and break down large molecules; anabolic pathways are endergonic and build large molecules.

Question 3

Which of the following is NOT a function of ATP in microbial metabolism?

Accepted Answer

Directly transferring electrons to the electron transport chain

Question 4

Which of the following equations correctly represents substrate-level phosphorylation?

Accepted Answer

$$	ext{Substrate-P} + \mathrm{ADP} ightarrow 	ext{Substrate} + \mathrm{ATP}$$

Question 5

Which of the following is a correct pairing of enzyme class and reaction type?

Accepted Answer

Isomerase – rearrangement of atoms within a molecule

Question 6

Apoenzymes require which of the following to become functional holoenzymes?

Accepted Answer

A cofactor (inorganic ion or coenzyme)

Question 7

Which of the following factors does NOT directly affect enzyme activity?

Accepted Answer

Genetic code of the organism

Question 8

Which of the following best describes noncompetitive inhibition?

Accepted Answer

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

Question 9

During glycolysis, what is the net gain of ATP, NADH, and pyruvic acid molecules from one molecule of glucose?

Accepted Answer

2 ATP, 2 NADH, 2 pyruvic acid

Question 10

Which of the following is the correct sequence of events in aerobic cellular respiration?

Accepted Answer

Glycolysis → Synthesis of acetyl-CoA → Krebs cycle → Electron transport chain

Question 11

In the electron transport chain, what is the primary function of the proton gradient?

Accepted Answer

To drive the phosphorylation of ADP to ATP via ATP synthase

Question 12

Which of the following is a final electron acceptor in anaerobic respiration?

Accepted Answer

$$\mathrm{NO}_3^-$$

Question 13

Why does fermentation regenerate NAD+ in cells?

Accepted Answer

To allow glycolysis to continue in the absence of a functional electron transport chain

Question 14

Which of the following best explains why electrons from NADH yield more ATP than those from FADH2 in the electron transport chain?

Accepted Answer

NADH donates electrons earlier in the chain, resulting in more protons pumped and more ATP generated.

Question 15

Which of the following is a product of the light-independent reactions (Calvin-Benson cycle) in photosynthesis?

Accepted Answer

Glucose

Question 16

Which of the following is a correct description of an amphibolic pathway?

Accepted Answer

A pathway that can function both catabolically and anabolically

Question 17

Why is feedback inhibition necessary for controlling anabolic pathways?

Accepted Answer

It prevents the overproduction of end products, conserving energy and resources.

Question 18

Which of the following is a real-life example of the importance of oxygen in microbial metabolism, as seen in tuberculosis infections?

Accepted Answer

Oxygen is required for Mycobacterium tuberculosis to perform aerobic respiration and grow actively in the lungs.

Question 19

Which of the following best explains why catabolism of amino acids results in ammonia and other nitrogenous wastes?

Accepted Answer

Deamination removes the amino group from amino acids, releasing ammonia.

Question 20

Which of the following is a key function of the pentose phosphate pathway?

Accepted Answer

Generation of precursor metabolites for nucleotide and amino acid synthesis

Microbial Metabolism: Foundations and Pathways CH-5

Study Guide - Practice Questions