$$\text{Disaccharide} + H_2O \rightarrow \text{Monosaccharide} + \text{Monosaccharide}$$

$$\text{Fatty Acid} + \text{CoA} + \text{NAD}^+ + \text{FAD} \rightarrow \text{Acetyl-CoA} + \text{NADH} + \text{FADH}_2$$

Question 1

Which of the following best describes the role of enzymes in biological reactions?

Accepted Answer

Enzymes lower the activation energy, speeding up reactions without being consumed.

Question 2

A competitive inhibitor affects an enzyme by:

Accepted Answer

Binding to the active site, preventing the substrate from binding.

Question 3

Which equation correctly represents the formation of ATP from ADP?

Accepted Answer

$$\mathrm{ADP} + \mathrm{P}_i \rightarrow \mathrm{ATP}$$

Question 4

Which environmental factor is most likely to cause irreversible denaturation of an enzyme?

Accepted Answer

A temperature above the enzyme's optimum.

Question 5

During glycolysis, what is the net gain of ATP molecules per molecule of glucose?

Accepted Answer

2 ATP

Question 6

Which pathway allows cells to recycle NAD+ in the absence of oxygen?

Accepted Answer

Fermentation

Question 7

Which of the following is a correct equation for the reduction of NAD+ during glycolysis?

Accepted Answer

$$\mathrm{NAD}^+ + 2e^- + 2H^+ \rightarrow \mathrm{NADH} + H^+$$

Question 8

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

Accepted Answer

Pyruvate

Question 9

In oxidative phosphorylation, what is the terminal electron acceptor in aerobic respiration?

Accepted Answer

Oxygen

Question 10

Which process occurs in the thylakoid membrane of chloroplasts and results in the production of ATP and NADPH?

Accepted Answer

Light reactions (photophosphorylation)

Question 11

Which of the following best explains why enzymes are highly specific for their substrates?

Accepted Answer

The active site of the enzyme has a unique three-dimensional shape that fits only specific substrates.

Question 12

Which of the following is a coenzyme that is NOT synthesized by the host and must be obtained from vitamins?

Accepted Answer

NAD+

Question 13

Which equation represents the hydrolysis of a disaccharide?

Accepted Answer

$$	ext{Disaccharide} + H_2O ightarrow 	ext{Monosaccharide} + 	ext{Monosaccharide}$$

Question 14

Which of the following is a fast method for controlling enzyme activity in cells?

Accepted Answer

Inhibition by molecules binding to the enzyme

Question 15

Which pathway is primarily used by prokaryotes and yields precursor metabolites and NADPH with reduced ATP production?

Accepted Answer

Entner-Doudoroff Pathway

Question 16

Which of the following is a correct equation for the beta-oxidation of fatty acids?

Accepted Answer

$$	ext{Fatty Acid} + 	ext{CoA} + 	ext{NAD}^+ + 	ext{FAD} ightarrow 	ext{Acetyl-CoA} + 	ext{NADH} + 	ext{FADH}_2$$

Question 17

Which of the following is a product of the light reactions in photosynthesis?

Accepted Answer

NADPH

Question 18

Which of the following is a result of feedback inhibition in a metabolic pathway?

Accepted Answer

The final product binds to the first enzyme, shutting down the pathway.

Question 19

Which of the following is a correct equation for the dark reactions (Calvin cycle) of photosynthesis?

Accepted Answer

$$\mathrm{CO}_2 + \mathrm{NADPH} + \mathrm{ATP} ightarrow 	ext{Glucose} + \mathrm{NADP}^+ + \mathrm{ADP}$$

Microbial Metabolism: Enzymes, Energy, and Biochemical Pathways

Study Guide - Practice Questions