Question 1

Which of the following best describes the role of enzymes in metabolic pathways?

Accepted Answer

Enzymes lower the activation energy of reactions, allowing them to proceed faster without being altered.

Question 2

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Competing for the enzyme's active site, blocking substrate binding.

Question 3

Which equation correctly represents the oxidation of NADH during cellular respiration?

Accepted Answer

$$\mathrm{NADH} + H^+ \rightarrow \mathrm{NAD}^+ + 2e^- + 2H^+$$

Question 4

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

Accepted Answer

Oxygen ($$O_2)$$

Question 5

Which metabolic pathway is used by both aerobic and anaerobic organisms to break down glucose?

Accepted Answer

Glycolysis

Question 6

What is the net ATP yield from glycolysis per molecule of glucose?

Accepted Answer

$$2$$ ATP

Question 7

Which of the following statements about feedback inhibition is correct?

Accepted Answer

The end product binds to an allosteric site, causing noncompetitive inhibition of the pathway's first enzyme.

Question 8

Which process is responsible for the conversion of light energy into chemical energy in photosynthetic organisms?

Accepted Answer

Light-dependent reactions

Question 9

Which of the following is a correct description of an amphibolic pathway?

Accepted Answer

A pathway that functions in both anabolism and catabolism.

Question 10

Which enzyme class catalyzes the joining of molecules and uses ATP?

Accepted Answer

Ligase

Question 11

A bacterium is found to metabolize glucose using the Entner-Doudoroff pathway. Which of the following is true?

Accepted Answer

It produces NADPH, NADH, and ATP independently of glycolysis.

Question 12

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

Accepted Answer

2 FADH$$_2$$

Question 13

Which statement best explains why high temperature can inhibit enzyme activity?

Accepted Answer

High temperature denatures the enzyme, altering its active site.

Question 14

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

Accepted Answer

$$ADP + P_i \rightarrow ATP$$

Question 15

Which of the following is true about ribozymes?

Accepted Answer

Ribozymes are RNA molecules that catalyze reactions and are not used up in the process.

Question 16

Which of the following is a correct description of catabolic reactions?

Accepted Answer

Catabolic reactions break down complex molecules and release energy.

Question 17

Which of the following is a correct equation for the reduction of oxygen in the electron transport chain?

Accepted Answer

$$O_2 + 4e^- + 4H$$^+ \rightarrow 2H_2O$$

Question 18

Which of the following is a product of alcoholic fermentation?

Accepted Answer

Ethanol

Question 19

Which of the following best describes the role of NADH in cellular respiration?

Accepted Answer

NADH donates electrons to the electron transport chain, helping generate ATP.

Question 20

Which of the following is true about substrate concentration and enzyme activity?

Accepted Answer

Enzyme activity increases with substrate concentration until saturation is reached.

Microbial Metabolism: Study Notes for College Microbiology

Study Guide - Practice Questions