Question 1

Which of the following best describes the difference between catabolic and anabolic pathways in microbial metabolism?

Accepted Answer

Catabolic pathways break down substances to release energy, while anabolic pathways use energy to build new substances.

Question 2

A cell is observed to be breaking down glucose into carbon dioxide and water, releasing energy in the process. Which type of metabolic reaction is this, and what is the general equation for the process?

Accepted Answer

Anabolic reaction; $$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2 ightarrow 6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} + 	ext{energy}$$

Question 3

Why is ATP considered an ideal energy molecule for cells?

Accepted Answer

ATP contains high-energy phosphate bonds that can be easily broken to release energy for cellular work.

Question 4

Which of the following statements about the ATP/ADP cycle is correct?

Accepted Answer

Energy is released when ATP is hydrolyzed to ADP, and ATP is regenerated from ADP by phosphorylation.

Question 5

A scientist is studying an enzyme-catalyzed reaction. Which of the following best explains how enzymes speed up chemical reactions?

Accepted Answer

Enzymes lower the activation energy required for the reaction to proceed.

Question 6

Which of the following is a correct example of a coenzyme and its function?

Accepted Answer

NAD+; accepts electrons during redox reactions in catabolic pathways

Question 7

A bacterial culture is incubated at a temperature above the optimal range for its enzymes. What is the most likely effect on enzyme activity and why?

Accepted Answer

Enzyme activity will decrease due to denaturation of the enzyme's structure.

Question 8

Which of the following best describes feedback inhibition in a metabolic pathway?

Accepted Answer

The end product of a pathway binds to an allosteric site on an enzyme early in the pathway, decreasing its activity.

Question 9

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

Accepted Answer

2 ATP and 2 NADH

Question 10

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

Accepted Answer

The ETC is located in the plasma membrane.

Question 11

A patient with diabetes is found to have ketoacidosis. Which metabolic process is most likely increased in this patient, and what is the consequence for blood pH?

Accepted Answer

Increased lipid catabolism; blood pH decreases

Question 12

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

Accepted Answer

Aerobic respiration uses oxygen as the final electron acceptor, while anaerobic respiration uses an inorganic molecule other than oxygen.

Question 13

Which of the following best explains why fermentation is less efficient than aerobic respiration in terms of ATP yield?

Accepted Answer

Fermentation does not use the electron transport chain, so less ATP is produced per glucose molecule.

Question 14

A bacterium is found to be oxidase negative. What does this indicate about its electron transport chain?

Accepted Answer

It lacks cytochrome c oxidase and may use a different terminal oxidase.

Question 15

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

Accepted Answer

ATP is generated by transferring a phosphate group directly from a high-energy substrate to ADP.

Question 16

Which pathway is primarily responsible for generating NADPH for anabolic reactions in bacteria?

Accepted Answer

Entner-Doudoroff pathway

Question 17

A microbe is able to grow in the absence of oxygen by using nitrate ($$\mathrm{NO}_3^-) as a $$final electron acceptor. Which process is this microbe performing?

Accepted Answer

Anaerobic respiration

Question 18

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

Accepted Answer

Beta-oxidation breaks down fatty acids into acetyl-CoA, which enters the Krebs cycle.

Question 19

Which of the following statements about gluconeogenesis is correct?

Accepted Answer

Gluconeogenesis is the process of synthesizing glucose from non-sugar precursors.

Microbial Metabolism: Foundations and Enzyme Function Chapter 8

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