Question 1

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP couples exergonic (catabolic) and endergonic (anabolic) reactions by storing and transferring energy.

Question 2

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

Accepted Answer

Oxidative phosphorylation via the electron transport chain

Question 3

What is the main function of NADH and FADH$$_2 in $$aerobic respiration?

Accepted Answer

They serve as electron carriers, donating electrons to the electron transport chain.

Question 4

Which of the following statements about enzymes is FALSE?

Accepted Answer

Enzymes are altered by the reactions they catalyze.

Question 5

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 6

Why do sulfa drugs selectively inhibit bacterial metabolism but not human metabolism?

Accepted Answer

Sulfa drugs outcompete PABA in the bacterial folic acid pathway, which humans do not possess.

Question 7

Which of the following best explains why enzyme activity levels off at high substrate concentrations?

Accepted Answer

All enzyme active sites are saturated with substrate, so the reaction rate cannot increase further.

Question 8

Which of the following is a product of glycolysis?

Accepted Answer

Pyruvate

Question 9

In the electron transport chain, what is the final electron acceptor in aerobic respiration?

Accepted Answer

O$$_2$$

Question 10

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

Accepted Answer

It prevents the accumulation of end products by inhibiting an early enzyme in the pathway.

Question 11

Which of the following statements about redox reactions in metabolism is TRUE?

Accepted Answer

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

Question 12

Which pathway is used by some bacteria as an alternative to glycolysis and produces NADPH and ATP?

Accepted Answer

Entner-Doudoroff pathway

Question 13

What is the main reason why most ATP is generated during oxidative phosphorylation rather than substrate-level phosphorylation?

Accepted Answer

The electron transport chain creates a proton gradient that drives ATP synthase to produce large amounts of ATP.

Question 14

Which of the following is NOT a characteristic of enzymes?

Accepted Answer

They are consumed in the reactions they catalyze.

Question 15

Which of the following best explains why increasing temperature beyond an enzyme's optimal range decreases its activity?

Accepted Answer

The enzyme denatures, losing its functional three-dimensional structure.

Question 16

During the Krebs cycle, for each acetyl CoA molecule entering the cycle, how many molecules of NADH are produced?

Accepted Answer

3

Question 17

Which of the following is a direct result of the flow of protons (H$$^+) $$through ATP synthase during chemiosmosis?

Accepted Answer

Synthesis of ATP from ADP and P$$_i$$

Question 18

Which of the following statements about substrate-level phosphorylation is TRUE?

Accepted Answer

It involves the direct transfer of a phosphate group to ADP from a high-energy substrate.

Question 19

Which of the following is a function of coenzymes in metabolism?

Accepted Answer

They act as non-protein carriers of small molecules or electrons, often derived from vitamins.

Question 20

Which of the following best describes the fate of glucose during aerobic respiration?

Accepted Answer

Glucose is completely oxidized to CO$$_2$$ and H$$_2O$$, with energy captured in ATP.

Microbial Metabolism: Pathways, Enzymes, and Energy Production

Study Guide - Practice Questions