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

Question 1

Which of the following best describes the difference between catabolism and anabolism in cellular metabolism?

Accepted Answer

Catabolism breaks down complex molecules to release energy, while anabolism uses energy to build complex molecules from simpler ones.

Question 2

During glycolysis, which of the following is a direct product?

Accepted Answer

Pyruvate

Question 3

Which equation correctly represents the oxidation of glucose during aerobic respiration?

Accepted Answer

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

Question 4

What is the primary role of NAD+ and FAD in cellular respiration?

Accepted Answer

They function as electron carriers, accepting electrons during redox reactions.

Question 5

Which of the following best describes the effect of temperature on enzyme activity?

Accepted Answer

Enzyme activity increases with temperature up to an optimum, then decreases due to denaturation.

Question 6

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site, preventing substrate binding.

Question 7

Which of the following is a correct statement about feedback inhibition?

Accepted Answer

The end product of a metabolic pathway inhibits an enzyme involved early in the pathway.

Question 8

Which of the following best differentiates fermentation from aerobic respiration?

Accepted Answer

Fermentation uses an organic molecule as the final electron acceptor, while aerobic respiration uses oxygen.

Question 9

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

Accepted Answer

Lactic acid

Question 10

In the pentose phosphate pathway, which of the following is a major product that distinguishes it from glycolysis?

Accepted Answer

NADPH

Question 11

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

Accepted Answer

Nitrate ($$NO_3$$^-$$)

Question 12

A patient’s cells are exposed to a pH far outside their normal range. What is the most likely effect on enzyme activity?

Accepted Answer

Enzyme activity will decrease due to denaturation.

Question 13

Which of the following best explains why glycolysis can occur in both aerobic and anaerobic conditions?

Accepted Answer

Glycolysis does not require oxygen and produces ATP via substrate-level phosphorylation.

Question 14

Which of the following is a correct summary of the connection between catabolism and anabolism?

Accepted Answer

Catabolism provides the energy and building blocks for anabolism.

Question 15

Which of the following is a key difference between the Enter-Doudoroff pathway and glycolysis?

Accepted Answer

The Enter-Doudoroff pathway produces NADPH and ATP, while glycolysis produces only ATP.

Question 16

Which of the following is NOT a typical end product of fermentation?

Accepted Answer

Oxygen

Question 17

A noncompetitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to an allosteric site, changing the enzyme's shape and reducing activity.

Question 18

Which of the following best describes the fate of NADH during fermentation?

Accepted Answer

NADH is oxidized to NAD$$^+$$, allowing glycolysis to continue.

Question 19

Which of the following is a correct statement about the structure of enzymes?

Accepted Answer

Enzymes are proteins with a specific three-dimensional shape essential for their function.

Question 20

Which of the following best explains why increasing substrate concentration increases enzyme activity only up to a certain point?

Accepted Answer

All enzyme active sites become saturated, so adding more substrate does not increase the rate.

Microbial Metabolism: Enzymes, Pathways, and Energy Production

Study Guide - Practice Questions