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 down molecules and are exergonic, while anabolic pathways build molecules and are endergonic.

Question 3

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

Accepted Answer

2 ATP and 2 NADH

Question 4

Which of the following equations correctly represents substrate-level phosphorylation?

Accepted Answer

$$ \mathrm{Substrate{-}P} + \mathrm{ADP} \rightarrow \mathrm{Product} + \mathrm{ATP} $$

Question 5

Which of the following is NOT a function of electron carriers such as NAD+, NADP+, and FAD?

Accepted Answer

Acting as final electron acceptors in the electron transport chain

Question 6

A patient is diagnosed with a genetic disorder that prevents the formation of holoenzymes. Which of the following is most likely impaired in this patient?

Accepted Answer

The ability to form active enzymes from apoenzymes and cofactors

Question 7

Which of the following best explains why enzymes are considered biological catalysts?

Accepted Answer

They lower the activation energy and increase the rate of chemical reactions.

Question 8

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and blocking substrate binding

Question 9

Which of the following is a correct summary of the products of the Krebs cycle per molecule of glucose?

Accepted Answer

2 ATP, 2 FADH2, 6 NADH, 4 CO2

Question 10

In the electron transport chain, what is the primary role of the proton gradient?

Accepted Answer

To drive the synthesis of ATP via ATP synthase

Question 11

Which of the following best describes the process of chemiosmosis?

Accepted Answer

The use of a proton gradient to drive the phosphorylation of ADP to ATP

Question 12

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

Accepted Answer

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

Question 13

Which pathway provides an alternative to glycolysis and is important for generating NADPH and ribose-5-phosphate for anabolic reactions?

Accepted Answer

Pentose phosphate pathway

Question 14

During fermentation, what is the primary purpose of reducing pyruvate to lactic acid or ethanol?

Accepted Answer

To regenerate NAD+ for glycolysis

Question 15

Which of the following best describes the role of chlorophyll in photosynthesis?

Accepted Answer

It captures light energy and initiates electron transfer reactions.

Question 16

Which of the following equations represents the overall reaction of the Calvin-Benson cycle?

Accepted Answer

$$ 6 \mathrm{CO_2$} + 18 \mathrm{ATP} + 12 \mathrm{NADPH} + 12 \mathrm{H_2O} \rightarrow \mathrm{C_6H_{12}O_6$} + 18 \mathrm{ADP} + 18 \mathrm{P_i} + 12 \mathrm{NADP^+} + 6 \mathrm{H^+} $$

Question 17

A cell is exposed to a noncompetitive inhibitor. What is the most likely effect on the enzyme's activity?

Accepted Answer

The inhibitor binds to an allosteric site, changing the enzyme's shape and reducing activity.

Question 18

Which of the following regulatory mechanisms allows a cell to slow or stop an anabolic pathway when the end product is abundant?

Accepted Answer

Feedback inhibition

Question 19

Which of the following best describes an amphibolic pathway?

Accepted Answer

A pathway that can function in both catabolic and anabolic processes

Question 20

A bacterium is growing in an environment with both glucose and lactose available. According to metabolic regulation principles, which energy source will the cell catabolize first and why?

Accepted Answer

Glucose, because it is more energy efficient to catabolize

Microbial Metabolism: Key Concepts and Pathways

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