$$2 \text{ ATP}, 2 \text{ NADH}, 2 \text{ pyruvic acid}$$

$$2 \text{ ATP}, 6 \text{ NADH}, 2 \text{ FADH}_2, 4 \text{ CO}_2$$

Question 1

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

Accepted Answer

Catabolism breaks down complex molecules to release energy, which is then used by anabolism to synthesize complex molecules from simpler ones.

Question 2

Which of the following is a correct representation of the net products of glycolysis from one molecule of glucose?

Accepted Answer

$$2 	ext{ ATP}, 2 	ext{ NADH}, 2 	ext{ pyruvic acid}$$

Question 3

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

Accepted Answer

Oxygen ($$O_2)$$

Question 4

Which of the following best explains why cells use fermentation pathways?

Accepted Answer

To regenerate NAD+ when oxygen is not available for cellular respiration.

Question 5

Which of the following is NOT a function of enzymes in metabolism?

Accepted Answer

Being consumed and permanently altered during reactions.

Question 6

Apoenzymes require which of the following to become functional holoenzymes?

Accepted Answer

Binding to non-protein cofactors such as inorganic ions or coenzymes.

Question 7

Which of the following statements about oxidation-reduction (redox) reactions is correct?

Accepted Answer

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

Question 8

Which of the following is a product of the Krebs cycle for each glucose molecule (two turns)?

Accepted Answer

$$2 	ext{ ATP}, 6 	ext{ NADH}, 2 	ext{ FADH}_2, 4 	ext{ CO}_2$$

Question 9

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

ATP is generated directly by the transfer of a phosphate group from a substrate to ADP.

Question 10

Which of the following is a key regulatory mechanism that cells use to control metabolic pathways?

Accepted Answer

Feedback inhibition, where the end product of a pathway inhibits an earlier enzyme.

Question 11

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

Accepted Answer

The ETC uses the energy from electrons to pump protons across a membrane, creating a proton gradient.

Question 12

Which of the following is true about the Calvin-Benson cycle?

Accepted Answer

It fixes carbon dioxide into organic molecules using ATP and NADPH.

Question 13

Which of the following is a correct description of chemiosmosis?

Accepted Answer

The use of a proton gradient to drive the synthesis of ATP via ATP synthase.

Question 14

Which of the following is NOT a type of enzyme based on mode of action?

Accepted Answer

Polymerases

Question 15

Which of the following statements about amphibolic pathways is correct?

Accepted Answer

They are pathways that can function in both catabolic and anabolic processes.

Question 16

Which of the following is a reason why cells might use the pentose phosphate pathway instead of glycolysis?

Accepted Answer

To produce NADPH and ribose-5-phosphate for anabolic reactions.

Question 17

Which of the following is a correct statement about the effect of temperature on enzyme activity?

Accepted Answer

Enzyme activity is highest at an optimal temperature and decreases if the temperature is too high or too low.

Question 18

Which of the following best describes noncompetitive inhibition of an enzyme?

Accepted Answer

An inhibitor binds to an allosteric site, changing the enzyme's shape and reducing its activity.

Question 19

Which of the following is a product of lipid catabolism that can enter the Krebs cycle?

Accepted Answer

Acetyl-CoA

Microbial Metabolism: Chemical Reactions and Pathways

Study Guide - Practice Questions