Question 1

Which of the following best describes the relationship between catabolism and anabolism in cellular metabolism?

Accepted Answer

Catabolism breaks down complex molecules to release energy, which is then used by anabolism to build complex molecules from simpler ones.

Question 2

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

Accepted Answer

2 ATP and 2 NADH

Question 3

Which of the following statements about oxidation-reduction (redox) reactions is correct?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 4

Which of the following is NOT a way that cells phosphorylate ADP to ATP?

Accepted Answer

Hydrolytic phosphorylation

Question 5

Apoenzymes require which of the following to become functional holoenzymes?

Accepted Answer

A cofactor (inorganic ion or coenzyme)

Question 6

Which of the following factors does NOT directly affect the rate of enzymatic reactions?

Accepted Answer

The genetic code of the organism

Question 7

In the electron transport chain (ETC) of aerobic respiration, what is the final electron acceptor?

Accepted Answer

Oxygen ($O_2$)

Question 8

Which of the following best explains why fermentation is necessary in some cells?

Accepted Answer

Fermentation provides a constant source of NAD+ by oxidizing NADH, allowing glycolysis to continue in the absence of a functional electron transport chain.

Question 9

Which of the following is a correct description of the role of ATP in metabolism?

Accepted Answer

ATP stores energy in high-energy phosphate bonds and provides energy for anabolic reactions by breaking these bonds.

Question 10

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

Accepted Answer

2 ATP, 2 FADH2, 6 NADH, and 4 CO2

Question 11

Which of the following best describes the function of electron carriers such as NAD+, NADP+, and FAD in metabolism?

Accepted Answer

They transfer electrons between molecules during redox reactions, facilitating energy transfer.

Question 12

Which of the following is a distinguishing feature of noncompetitive enzyme inhibition?

Accepted Answer

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

Question 13

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 from the light-dependent reactions.

Question 14

A patient is diagnosed with a genetic disorder that prevents the synthesis of a specific coenzyme required for a key metabolic enzyme. Which of the following is the most likely consequence?

Accepted Answer

The enzyme will be unable to function, leading to a buildup of substrate and a deficiency of product.

Question 15

Which of the following best explains why cells regulate metabolic pathways using feedback inhibition?

Accepted Answer

To prevent the overproduction of end products and conserve resources.

Question 16

Which of the following is a correct statement about amphibolic pathways?

Accepted Answer

They are metabolic pathways that can function in both anabolic and catabolic processes.

Question 17

A researcher is studying a bacterium that can use both glucose and lactose as energy sources. When both sugars are present, the bacterium preferentially uses glucose. Which regulatory principle does this illustrate?

Accepted Answer

Catabolite repression (preferential use of the more energy-efficient substrate)

Question 18

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 phosphorylated substrate to ADP.

Question 19

Which of the following is a real-world example of the importance of enzyme specificity?

Accepted Answer

A patient with phenylketonuria (PKU) cannot metabolize phenylalanine due to a defective enzyme, leading to toxic buildup.

Microbial Metabolism: Foundations, Pathways, and Regulation

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