Question 1

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

Accepted Answer

To reproduce the organism by coordinating controlled biochemical reactions

Question 2

Which statement correctly distinguishes between catabolic and anabolic pathways?

Accepted Answer

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

Question 3

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

Accepted Answer

$$2$$

Question 4

Which of the following is NOT a correct pairing of an electron carrier with its function?

Accepted Answer

ATP – carries electrons as part of hydrogen atoms

Question 5

Which process is responsible for the majority of ATP production during aerobic respiration in prokaryotes?

Accepted Answer

Electron transport chain and chemiosmosis

Question 6

A patient with a mitochondrial disorder has impaired oxidative phosphorylation. Which step of ATP production is most directly affected?

Accepted Answer

ATP synthesis via the electron transport chain

Question 7

Which of the following best explains why 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 8

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 from a substrate to ADP.

Question 9

Which enzyme class is responsible for catalyzing the transfer of functional groups between molecules?

Accepted Answer

Transferases

Question 10

Apoenzymes require which of the following to become functional?

Accepted Answer

A cofactor (inorganic ion or coenzyme)

Question 11

Which of the following best describes allosteric activation of an enzyme?

Accepted Answer

A molecule binds to a site other than the active site, causing the active site to become functional.

Question 12

Which of the following is a key difference between competitive and noncompetitive enzyme inhibition?

Accepted Answer

Competitive inhibitors bind to the active site, while noncompetitive inhibitors bind to a different site on the enzyme.

Question 13

In the absence of oxygen, which process allows cells to regenerate NAD	extsuperscript{+} for glycolysis?

Accepted Answer

Fermentation

Question 14

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

Accepted Answer

$$2$$ molecules of ATP, $$6$$ molecules of NADH, $$2$$ molecules of $$FADH_2$$, and $$4$$ molecules of $$CO_2$$

Question 15

Which of the following statements about the Calvin-Benson cycle is correct?

Accepted Answer

It fixes carbon dioxide into organic molecules using ATP and NADPH.

Question 16

Which of the following best explains why feedback inhibition is necessary for controlling anabolic pathways?

Accepted Answer

It ensures that the end product of a pathway does not accumulate in excess, conserving energy and resources.

Question 17

Which of the following is a correct description of chemiosmosis in cellular respiration?

Accepted Answer

The use of a proton gradient across a membrane to drive the synthesis of ATP via ATP synthase

Question 18

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

Accepted Answer

Amino acids contain nitrogen, which is released as ammonia during deamination.

Question 19

Which of the following statements about the Entner-Doudoroff (ED) pathway is correct?

Accepted Answer

It produces less ATP than glycolysis and is unique to some prokaryotes.

Ch. 5 - Microbial Metabolism: Fundamental Chemical Reactions and Pathways

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