$$1\ \text{glucose} \rightarrow 2\ \text{pyruvate} + 2\ \text{ATP (net)} + 2\ \text{NADH}$$

Question 1

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP stores energy released from catabolic reactions and supplies energy for anabolic reactions.

Question 2

Which of the following statements about enzymes is CORRECT?

Accepted Answer

Enzymes provide a physical site for substrate molecules to position and lower the activation energy.

Question 3

Apoenzyme refers to:

Accepted Answer

The protein portion of an enzyme, without its cofactor.

Question 4

Which of the following is an example of an organic cofactor?

Accepted Answer

NAD$$^+$$

Question 5

What is the effect of increasing substrate concentration on enzyme activity, assuming enzyme concentration is constant?

Accepted Answer

The reaction rate increases and then levels off when all active sites are occupied.

Question 6

Which of the following best describes competitive inhibition?

Accepted Answer

The inhibitor binds to the active site, preventing substrate binding.

Question 7

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

Accepted Answer

Oxygen (O$$_2)$$

Question 8

Which process directly generates the most ATP during aerobic respiration of one glucose molecule in prokaryotes?

Accepted Answer

Electron transport chain and chemiosmosis

Question 9

Which of the following is TRUE regarding fermentation?

Accepted Answer

Fermentation regenerates NAD$$^+$$ from NADH to allow glycolysis to continue.

Question 10

Which of the following equations correctly represents the net ATP yield from glycolysis of one glucose molecule?

Accepted Answer

$$1\ 	ext{glucose} ightarrow 2\ 	ext{pyruvate} + 2\ 	ext{ATP (net)} + 2\ 	ext{NADH}$$

Question 11

Which of the following best explains why high temperatures can denature enzymes?

Accepted Answer

High temperatures disrupt the hydrogen bonds and other interactions that maintain protein structure.

Question 12

Which of the following is a correct description of oxidative phosphorylation?

Accepted Answer

ATP is generated using energy from the electron transport chain and a proton gradient.

Question 13

In the Krebs cycle, what is the main function of NAD$$^+$$?

Accepted Answer

To accept electrons and become reduced to NADH.

Question 14

Which of the following is a key difference between aerobic and anaerobic respiration?

Accepted Answer

Aerobic respiration uses O$$_2 as $$the final electron acceptor, while anaerobic respiration uses other inorganic molecules.

Question 15

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway binds to an allosteric site on the first enzyme, inhibiting its activity.

Question 16

Which of the following is a correct summary of the redox reaction involving NAD$$^+$$?

Accepted Answer

$$	ext{NAD}^+ + 2	ext{H} ightarrow 	ext{NADH} + 	ext{H}^+$$

Question 17

Which of the following is NOT a function of the electron transport chain?

Accepted Answer

To directly synthesize glucose from CO$$_2$$ and H$$_2O.$$

Question 18

Which of the following is a product of the intermediate (preparatory) step between glycolysis and the Krebs cycle?

Accepted Answer

Acetyl CoA

Question 19

Which of the following statements about substrate-level phosphorylation is TRUE?

Accepted Answer

It involves the direct transfer of a phosphate group to ADP from a phosphorylated substrate.

Question 20

Which of the following is a possible end product of fermentation in bacteria?

Accepted Answer

Lactic acid

Microbial Metabolism: Catabolism, Anabolism, and Energy Production

Study Guide - Practice Questions