Question 1

Which of the following best describes the role of catabolism in microbial metabolism?

Accepted Answer

Catabolism releases energy by breaking down complex molecules.

Question 2

A chemolithotroph obtains energy by oxidizing which of the following?

Accepted Answer

Inorganic compounds such as $\mathrm{H_2S}$ or $\mathrm{NH_4^+}$.

Question 3

Which equation correctly represents the reduction of NAD$^+$ to NADH?

Accepted Answer

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

Question 4

What is the main function of enzymes in cellular metabolism?

Accepted Answer

Enzymes lower the activation energy and increase reaction rates.

Question 5

Which of the following statements about prosthetic groups and coenzymes is correct?

Accepted Answer

Prosthetic groups are tightly bound, while coenzymes are loosely bound and often derived from vitamins.

Question 6

During substrate-level phosphorylation, how is ATP generated?

Accepted Answer

By transferring a phosphate group from an energy-rich organic compound directly to ADP.

Question 7

Which of the following is a correct description of fermentation?

Accepted Answer

Fermentation is an anaerobic process where organic compounds serve as both electron donors and acceptors.

Question 8

In the electron transport chain of eukaryotes, what is the final electron acceptor?

Accepted Answer

Molecular oxygen ($\mathrm{O_2}$)

Question 9

Which of the following best explains the generation of the proton motive force during respiration?

Accepted Answer

Protons are released to the outside of the membrane, creating a pH gradient and electrochemical potential.

Question 10

Which metabolic pathway is common to both fermentation and respiration in chemoorganotrophs?

Accepted Answer

Glycolysis (Embden–Meyerhof–Parnas pathway)

Question 11

Which of the following is NOT a possible terminal electron acceptor in anaerobic respiration?

Accepted Answer

Oxygen ($\mathrm{O_2}$)

Question 12

Which class of microorganisms uses light energy to generate ATP?

Accepted Answer

Phototrophs

Question 13

What is the main difference between the lock-and-key and induced fit models of enzyme activity?

Accepted Answer

The lock-and-key model suggests the active site is a perfect fit for the substrate, while the induced fit model suggests the active site changes shape upon substrate binding.

Question 14

Which of the following is a long-term energy storage molecule in prokaryotes?

Accepted Answer

Poly-β-hydroxybutyrate

Question 15

Which process is responsible for the synthesis of glucose from non-carbohydrate precursors?

Accepted Answer

Gluconeogenesis

Question 16

In bacteria and eukarya, how are lipids typically assembled?

Accepted Answer

By adding fatty acids to glycerol.

Question 17

Which of the following statements about chemolithotrophy is correct?

Accepted Answer

Chemolithotrophs use inorganic compounds as electron donors and are often autotrophic.

Question 18

Which enzyme is responsible for incorporating ammonia into amino acids during biosynthesis?

Accepted Answer

Glutamine synthetase

Question 19

What is the effect of high temperature on most enzymes?

Accepted Answer

It can denature the enzyme, altering its shape and function.

Question 20

Which of the following is true about the electron transport chain in prokaryotes?

Accepted Answer

It is located in the cytoplasmic membrane.

Microbial Metabolism: Principles, Pathways, and Energy Conservation

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