Question 1

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

Accepted Answer

Catabolism breaks down nutrients to release energy, while anabolism uses energy to build macromolecules.

Question 2

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy of a reaction, allowing it to proceed faster.

Question 3

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 4

Which of the following is an example of a coenzyme?

Accepted Answer

Nicotinamide adenine dinucleotide (NAD)

Question 5

In the context of redox reactions, which statement is true?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 6

Which pathway is unique to prokaryotes and produces 1 ATP and 1 NADPH per glucose molecule?

Accepted Answer

Entner-Doudoroff pathway

Question 7

What is the net yield of ATP, NADH, and pyruvate from glycolysis of one glucose molecule?

Accepted Answer

$$2$$ ATP, $$2$$ NADH, $$2$$ pyruvate

Question 8

During aerobic respiration, what is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen ($$O_2)$$

Question 9

Which of the following best explains why the addition of more substrate can overcome the effect of a competitive inhibitor?

Accepted Answer

The substrate and inhibitor compete for the same active site, so increasing substrate concentration increases the chance of substrate binding.

Question 10

Which process is responsible for the majority of ATP production during aerobic respiration?

Accepted Answer

Electron transport chain (ETC) and oxidative phosphorylation

Question 11

What is the main purpose of fermentation in cells?

Accepted Answer

To regenerate NAD+ from NADH, allowing glycolysis to continue

Question 12

Which of the following is a correct equation for aerobic respiration?

Accepted Answer

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

Question 13

Which of the following statements about the electron transport chain (ETC) is FALSE?

Accepted Answer

The ETC directly produces ATP without the involvement of a proton gradient.

Question 14

Which of the following is a product of the bridge step between glycolysis and the Krebs cycle?

Accepted Answer

Acetyl-CoA

Question 15

A bacterium that uses light as an energy source and CO2 as a carbon source is classified as a:

Accepted Answer

Photoautotroph

Question 16

Which of the following statements about feedback inhibition is correct?

Accepted Answer

The end-product of a pathway acts as a noncompetitive inhibitor of an enzyme early in the pathway.

Question 17

Which of the following is true regarding the ATP yield from NADH and FADH2 in the electron transport chain?

Accepted Answer

1 NADH yields 3 ATP, and 1 FADH2 yields 2 ATP.

Question 18

Which of the following best describes the role of NAD+ in cellular respiration?

Accepted Answer

It acts as an electron carrier, accepting electrons during glycolysis and the Krebs cycle.

Question 19

Which of the following is NOT a possible final electron acceptor in anaerobic respiration?

Accepted Answer

Oxygen ($$O_2)$$

Question 20

Which of the following statements about gluconeogenesis is correct?

Accepted Answer

It is the reversal of the glycolytic pathway to synthesize glucose from non-carbohydrate precursors.

Microbial Metabolism: Enzymes, Pathways, and Energy Production

Study Guide - Practice Questions