$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} \rightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + \text{energy}$$

Question 1

Which of the following best describes a catabolic reaction in cellular metabolism?

Accepted Answer

A reaction that breaks down molecules and is exergonic, releasing energy.

Question 2

During ATP hydrolysis, which of the following occurs?

Accepted Answer

A phosphate group is removed from ATP, releasing energy.

Question 3

Which of the following statements about enzyme activity is CORRECT?

Accepted Answer

Enzymes lower the activation energy, making reactions proceed faster.

Question 4

A competitive inhibitor affects an enzyme by:

Accepted Answer

Binding to the active site, preventing substrate binding.

Question 5

Which coenzyme is the most common oxidized electron carrier used in aerobic cellular respiration?

Accepted Answer

NAD	extsuperscript{+}

Question 6

Which of the following best describes the process of oxidative phosphorylation?

Accepted Answer

ATP is produced using energy from electrons transferred through the electron transport chain to oxygen.

Question 7

Which of the following equations correctly represents aerobic cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} ightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + 	ext{energy}$$

Question 8

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

Accepted Answer

It occurs when a phosphate group is transferred from an organic molecule to ADP to form ATP.

Question 9

Which of the following statements about glycolysis is TRUE?

Accepted Answer

Glycolysis produces 2 ATP and 2 NADH per molecule of glucose.

Question 10

Which of the following is a function of coenzymes such as NAD	extsuperscript{+} and FAD in cellular respiration?

Accepted Answer

They serve as electron carriers, transporting high-energy electrons.

Question 11

A bacterium that uses the Entner-Doudoroff pathway instead of glycolysis will produce which of the following per glucose molecule?

Accepted Answer

1 ATP and 1 NADPH

Question 12

Which of the following best explains why sulfonamide antibiotics are selectively toxic to bacteria but not to human cells?

Accepted Answer

Sulfonamides inhibit folic acid synthesis, and humans obtain folic acid from their diet.

Question 13

Which of the following is an example of an induced fit model of enzyme activity?

Accepted Answer

The enzyme's active site changes shape slightly to mold to the substrate upon binding.

Question 14

Which of the following vitamins is required to make coenzyme A?

Accepted Answer

Vitamin B	extsubscript{5} (pantothenic acid)

Question 15

During the citric acid cycle (Krebs cycle), which of the following is produced per turn of the cycle?

Accepted Answer

1 ATP, 3 NADH, 1 FADH	extsubscript{2}, and 2 CO	extsubscript{2}

Question 16

Which of the following best describes the role of oxygen in aerobic cellular respiration?

Accepted Answer

Oxygen is the final electron acceptor, forming water.

Question 17

Which of the following statements about the pentose-phosphate pathway is TRUE?

Accepted Answer

It produces ribose-5-phosphate for nucleotide synthesis and NADPH for biosynthetic reactions.

Question 18

Which of the following is a correct statement about chemiosmosis in cellular respiration?

Accepted Answer

Chemiosmosis occurs when protons flow through ATP synthase, driving the synthesis of ATP from ADP and phosphate.

Question 19

Which of the following is a plausible consequence if an enzyme is exposed to a temperature significantly above its optimal range?

Accepted Answer

The enzyme may denature, losing its structure and function.

Question 20

Which of the following best describes a redox reaction in cellular respiration?

Accepted Answer

A reaction in which a molecule loses electrons (oxidation) and another gains electrons (reduction).

Microbial Metabolism: Chemical Reactions, Enzymes, and Energy Pathways

Study Guide - Practice Questions