Question 1

Which of the following best describes the ultimate function of metabolism in a microbe?

Accepted Answer

To reproduce the organism

Question 2

Which statement correctly differentiates catabolic and anabolic pathways?

Accepted Answer

Catabolic pathways break larger molecules into smaller products and release energy, while anabolic pathways build larger molecules and require energy.

Question 3

Which of the following is NOT a correct pairing of enzyme class and function?

Accepted Answer

Ligase – Splitting a chemical into smaller parts without using water

Question 4

Apoenzymes require which of the following to become functional holoenzymes?

Accepted Answer

Either inorganic cofactors or organic coenzymes

Question 5

Which of the following best explains why enzymes lower the activation energy of a chemical reaction?

Accepted Answer

They provide a different pathway with a lower energy requirement.

Question 6

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding

Question 7

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

Accepted Answer

2 ATP and 2 NADH

Question 8

Which of the following is the correct sequence of stages in cellular respiration?

Accepted Answer

Synthesis of acetyl-CoA → Krebs cycle → Electron transport chain

Question 9

In the electron transport chain, what is the main function of the proton gradient?

Accepted Answer

To drive the synthesis of ATP via ATP synthase

Question 10

Which of the following statements about fermentation is TRUE?

Accepted Answer

Fermentation uses an organic molecule as the final electron acceptor.

Question 11

Why do electrons carried by NADH allow for the production of more ATP than those carried by FADH$$_2$$?

Accepted Answer

NADH donates electrons earlier in the electron transport chain, resulting in more protons pumped and more ATP generated.

Question 12

Which of the following is a product of the Krebs cycle for each molecule of glucose?

Accepted Answer

2 ATP, 6 NADH, 2 FADH$$_2$$, and 4 CO$$_2$$

Question 13

Which of the following is NOT a function of precursor metabolites?

Accepted Answer

Directly generating ATP via oxidative phosphorylation

Question 14

Which of the following statements about photosynthesis is correct?

Accepted Answer

The Calvin-Benson cycle fixes CO$$_2$$ into organic molecules.

Question 15

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway inhibits an enzyme involved early in the pathway.

Question 16

A bacterium is growing in an environment lacking oxygen but is still able to oxidize glucose. Which of the following processes is most likely occurring?

Accepted Answer

Anaerobic respiration or fermentation

Question 17

Which of the following is a key difference between substrate-level phosphorylation and oxidative phosphorylation?

Accepted Answer

Substrate-level phosphorylation uses an organic molecule as a phosphate donor, while oxidative phosphorylation uses inorganic phosphate and a proton motive force.

Question 18

Which of the following is a reason why catabolism of amino acids results in ammonia and other nitrogenous wastes?

Accepted Answer

Amino acids contain nitrogen in their amine groups, which are removed during deamination.

Question 19

Which of the following regulatory mechanisms allows a cell to control the amount and timing of enzyme production?

Accepted Answer

Control of gene expression

Question 20

A patient with tuberculosis has a relapse after years of dormancy. Which metabolic principle explains why Mycobacterium tuberculosis becomes active again after tubercles rupture?

Accepted Answer

The bacteria gain access to oxygen, allowing aerobic respiration and energy production for growth.

Microbial Metabolism: Foundations, Pathways, and Regulation

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