Question 1

Which of the following best describes an amphibolic pathway?

Accepted Answer

A pathway that can function in both catabolic and anabolic processes.

Question 2

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

Accepted Answer

$$2$$

Question 3

Which enzyme class is responsible for transferring functional groups from one molecule to another?

Accepted Answer

Transferase

Question 4

A patient is exposed to a drug that acts as a noncompetitive inhibitor of a key metabolic enzyme. What is the most likely effect on the enzyme's activity?

Accepted Answer

The enzyme's activity will decrease and cannot be restored by increasing substrate concentration.

Question 5

Which of the following is the correct balanced equation for aerobic cellular respiration of glucose?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + 38\mathrm{ATP}$$

Question 6

Which molecule acts as the final electron acceptor in the electron transport chain during aerobic respiration?

Accepted Answer

O$$_2$$

Question 7

A mutation causes a bacterium to lack coenzyme A (CoA). Which metabolic process would be most directly affected?

Accepted Answer

Conversion of pyruvate to acetyl-CoA in the intermediate step

Question 8

Which of the following statements about feedback inhibition is correct?

Accepted Answer

It uses the end product of a pathway to inhibit an enzyme early in the pathway.

Question 9

Which of the following best explains why fats yield more ATP per gram than carbohydrates?

Accepted Answer

Fats contain more hydrocarbon bonds, making them more reduced and able to release more electrons during oxidation.

Question 10

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

ATP is generated by the direct transfer of a phosphate group to ADP from a phosphorylated intermediate.

Question 11

A competitive inhibitor of an enzyme will:

Accepted Answer

Bind to the active site and prevent substrate binding.

Question 12

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

Accepted Answer

$$2$$ ATP

Question 13

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

Accepted Answer

It acts as an electron carrier, becoming reduced to NADH during glycolysis and the Krebs cycle.

Question 14

Which of the following is a key difference between lactic acid fermentation and alcohol fermentation?

Accepted Answer

Alcohol fermentation produces ethanol and CO$$_2$$, while lactic acid fermentation produces only lactic acid.

Question 15

Which of the following statements about enzyme denaturation is correct?

Accepted Answer

Denaturation changes the enzyme's structure, often resulting in loss of function.

Question 16

Which of the following best explains why the electron transport chain is essential for aerobic respiration?

Accepted Answer

It generates a proton gradient used to synthesize ATP via ATP synthase.

Question 17

Which of the following is a function of the pentose phosphate pathway?

Accepted Answer

It generates NADPH and pentoses for anabolic reactions.

Question 18

Which of the following statements about ribozymes is correct?

Accepted Answer

Ribozymes are RNA molecules that act as enzymes, typically on other RNA molecules.

Question 19

A bacterial cell is growing in an environment lacking oxygen but containing nitrate (NO$$_3^-). $$Which process is most likely being used for energy production?

Accepted Answer

Anaerobic respiration with nitrate as the final electron acceptor

Question 20

Which of the following best describes the role of beta-oxidation in metabolism?

Accepted Answer

It breaks down fatty acids into two-carbon units that enter the Krebs cycle as acetyl-CoA.

Microbial Metabolism: Pathways, Enzymes, and Energy Production

Study Guide - Practice Questions

Study Guide - Flashcards