Question 1

Which of the following best describes a 'far from equilibrium' reaction in cellular metabolism?

Accepted Answer

A reaction whose rate is much greater than the reverse rate, often serving as a regulatory step in metabolic pathways.

Question 2

Which of the following is NOT a way that cells regulate metabolic flux?

Accepted Answer

Passive diffusion of metabolites

Question 3

Compare and contrast allosteric control and covalent modification in enzyme regulation. Which statement is correct?

Accepted Answer

Allosteric control involves non-covalent interactions with regulatory molecules, while covalent modification involves the addition or removal of chemical groups such as phosphate.

Question 4

Which of the following statements about ATP hydrolysis is TRUE?

Accepted Answer

The high energy of ATP hydrolysis is primarily due to the resonance stabilization of the phosphate groups.

Question 5

During glycolysis, how many net molecules of ATP are produced per molecule of glucose?

Accepted Answer

$$2$$

Question 6

Which enzyme in glycolysis catalyzes a group transfer reaction by transferring a phosphate from ATP to glucose?

Accepted Answer

Hexokinase

Question 7

Which statement correctly describes the role of NAD+ in glycolysis?

Accepted Answer

NAD+ acts as an electron acceptor, being reduced to NADH during the oxidation of glyceraldehyde-3-phosphate.

Question 8

Which of the following is a major consequence of a 'far from equilibrium' reaction in a metabolic pathway?

Accepted Answer

It serves as a key regulatory point, often controlling the overall flux through the pathway.

Question 9

Which of the following best describes the function of dehydrogenases in metabolism?

Accepted Answer

They catalyze the oxidation-reduction reactions by transferring electrons from substrates to cofactors such as NAD+ or FAD.

Question 10

In glycolysis, which step is considered the 'committed step' and why?

Accepted Answer

The conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, because it commits the substrate to glycolysis.

Question 11

Which statement about the Cori cycle is correct?

Accepted Answer

It describes the conversion of lactate to glucose in the liver and its transport back to muscle.

Question 12

Which of the following statements about gluconeogenesis and glycolysis is TRUE?

Accepted Answer

Gluconeogenesis bypasses the irreversible steps of glycolysis using different enzymes.

Question 13

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

Accepted Answer

Catalyzing the rearrangement of atoms within a molecule to form isomers.

Question 14

During lactic acid fermentation, which molecule is regenerated to allow glycolysis to continue under anaerobic conditions?

Accepted Answer

NAD+

Question 15

Which of the following is a correct statement about the role of phosphate group solvation in ATP hydrolysis?

Accepted Answer

Solvation stabilizes the products (ADP and Pi), contributing to the highly exergonic nature of ATP hydrolysis.

Question 16

Which cofactor is reduced during the oxidation of glyceraldehyde-3-phosphate in glycolysis?

Accepted Answer

NAD+

Question 17

Which enzyme catalyzes the conversion of fructose-1,6-bisphosphate to two 3-carbon products in glycolysis?

Accepted Answer

Aldolase

Question 18

Which of the following is a key difference between glycolysis and glycogen synthesis?

Accepted Answer

Glycolysis produces ATP, while glycogen synthesis consumes ATP.

Question 19

Which enzyme is responsible for the committed step in glycogen synthesis?

Accepted Answer

Glycogen synthase

Biochemistry Study Guide: Metabolic Pathways, Enzyme Regulation, and Energy Production -Module 6

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