Question 1

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

Accepted Answer

To reproduce the organism by coordinating biochemical reactions

Question 2

Which process is characterized as exergonic and involves breaking larger molecules into smaller products?

Accepted Answer

Catabolic pathway

Question 3

Cells store energy in adenosine triphosphate (ATP). Which equation correctly represents the formation of ATP from ADP and inorganic phosphate?

Accepted Answer

$$\mathrm{ADP} + \mathrm{P_i} \rightarrow \mathrm{ATP}$$

Question 4

Which electron carrier is NOT commonly used by cells in redox reactions?

Accepted Answer

Coenzyme Q10 (ubiquinone)

Question 5

Which type of phosphorylation occurs when ATP is generated directly from the transfer of a phosphate group to ADP from a substrate?

Accepted Answer

Substrate-level phosphorylation

Question 6

Apoenzymes require a cofactor to become active. What is the term for the complete, active enzyme?

Accepted Answer

Holoenzyme

Question 7

Which of the following factors does NOT directly affect the rate of enzymatic reactions?

Accepted Answer

Cellular motility

Question 8

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding

Question 9

Feedback inhibition is necessary for controlling anabolic pathways because:

Accepted Answer

It prevents the overproduction of products and conserves resources

Question 10

During glycolysis, one molecule of glucose is split into two molecules of which precursor metabolite?

Accepted Answer

Pyruvic acid

Question 11

Which metabolic pathway is less energy efficient than glycolysis and produces precursor metabolites and NADPH for biosynthesis?

Accepted Answer

Pentose Phosphate Pathway

Question 12

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

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 13

Chemiosmosis in cellular respiration involves:

Accepted Answer

Use of a proton gradient to drive ATP synthesis via ATP synthase

Question 14

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

Accepted Answer

38 ATP

Question 15

Why does catabolism of amino acids for energy result in ammonia and other nitrogenous wastes?

Accepted Answer

Because the amino group is removed during deamination, producing ammonia

Question 16

Which pigment is essential for capturing light energy in photosynthetic organisms and is structurally similar to cytochromes?

Accepted Answer

Chlorophyll

Question 17

Which regulatory mechanism allows cells to control the amount and timing of enzyme production?

Accepted Answer

Control of gene expression

Question 18

A bacterium is exposed to two energy sources. According to metabolic regulation principles, what will it do?

Accepted Answer

Catabolize the more energy-efficient source first

Question 19

Which of the following is NOT a precursor metabolite generated during glycolysis?

Accepted Answer

Oxaloacetate

Question 20

A mutation causes a bacterium to lose the ability to synthesize a coenzyme required for a key metabolic enzyme. What is the most likely consequence?

Accepted Answer

The enzyme will become inactive as an apoenzyme

Microbial Metabolism: Chemical Reactions and Pathways

Study Guide - Practice Questions