Question 1

Which of the following best describes the difference between catabolic and anabolic pathways in cellular metabolism?

Accepted Answer

Catabolic pathways break down macromolecules into simpler molecules, releasing energy, while anabolic pathways build up macromolecules from simpler molecules, using energy.

Question 2

Which of the following statements about enzymes is CORRECT?

Accepted Answer

Enzymes lower the activation energy required for a reaction to occur.

Question 3

Which of the following equations correctly represents the overall reaction for aerobic respiration of glucose?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} + 38\ \mathrm{ADP} + 38\ \mathrm{P_i} \rightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + 38\ \mathrm{ATP}$$

Question 4

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

Accepted Answer

Hydrolase – removes groups of atoms without hydrolysis

Question 5

A competitive inhibitor of an enzyme acts by:

Accepted Answer

Binding to the active site, preventing substrate binding

Question 6

Which vitamin is a component of NAD+ and is essential for electron transfer in metabolism?

Accepted Answer

Niacin (nicotinic acid)

Question 7

Which of the following best explains why enzymes are specific for their substrates?

Accepted Answer

The active site of an enzyme has a unique shape that only fits specific substrates.

Question 8

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

ATP is generated directly by transferring a phosphate group from a substrate to ADP.

Question 9

During glycolysis, what are the net products generated from one molecule of glucose?

Accepted Answer

2 pyruvate, 2 ATP, 2 NADH

Question 10

Which of the following is the correct sequence of events in aerobic respiration?

Accepted Answer

Glycolysis → Krebs cycle → Electron transport chain

Question 11

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

Accepted Answer

It is located in the plasma membrane.

Question 12

What is the final electron acceptor in aerobic respiration?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 13

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactic acid

Question 14

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

Accepted Answer

The end product of a pathway acts as a noncompetitive inhibitor of an enzyme early in the pathway.

Question 15

Which of the following is true regarding anaerobic respiration?

Accepted Answer

It generates less ATP than aerobic respiration.

Question 16

Which of the following is a correct statement about the role of NAD+ in metabolism?

Accepted Answer

NAD+ acts as an electron carrier, accepting electrons during redox reactions.

Question 17

Which of the following is a real-world example of selective toxicity involving enzyme inhibition?

Accepted Answer

Sulfanilamide inhibits folic acid synthesis in bacteria by acting as a competitive inhibitor of PABA.

Question 18

Which of the following best explains why high temperatures can denature enzymes?

Accepted Answer

High temperatures disrupt the hydrogen bonds and other interactions maintaining the enzyme's three-dimensional structure.

Question 19

Which of the following is a correct description of oxidative phosphorylation?

Accepted Answer

ATP is generated as electrons are passed down the electron transport chain and protons flow through ATP synthase.

Microbial Metabolism: Enzymes, Energy, and Pathways

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