Question 1

Which of the following best describes the two main phases of glycolysis?

Accepted Answer

An energy-investment phase and an energy-generation phase

Question 2

During the energy-investment phase of glycolysis, how many ATP molecules are consumed per molecule of glucose?

Accepted Answer

$$2$$

Question 3

Which enzyme catalyzes the phosphorylation of glucose to glucose-6-phosphate in the first step of glycolysis?

Accepted Answer

Hexokinase

Question 4

What is the net gain of ATP molecules per glucose molecule after glycolysis is complete?

Accepted Answer

$$2$$

Question 5

Which reaction in glycolysis is considered the major regulatory (control) point?

Accepted Answer

Phosphofructokinase (PFK) reaction

Question 6

Which of the following is a substrate-level phosphorylation step in glycolysis?

Accepted Answer

Phosphoglycerate kinase

Question 7

What is the fate of pyruvate under anaerobic conditions in muscle cells?

Accepted Answer

It is converted to lactate

Question 8

Which enzyme catalyzes the conversion of phosphoenolpyruvate (PEP) to pyruvate, generating ATP?

Accepted Answer

Pyruvate kinase

Question 9

Which three glycolytic enzymes catalyze reactions that must be bypassed in gluconeogenesis?

Accepted Answer

Hexokinase, phosphofructokinase, pyruvate kinase

Question 10

Which organ is the most active in gluconeogenesis, especially during fasting?

Accepted Answer

Liver

Question 11

Why must NADH be reoxidized to NAD$$^+$$ for glycolysis to continue under anaerobic conditions?

Accepted Answer

To allow the oxidation of glyceraldehyde-3-phosphate

Question 12

Which enzyme is responsible for cleaving $$\alpha(1 \rightarrow 4)$$ glycosidic bonds in glycogen during glycogenolysis?

Accepted Answer

Glycogen phosphorylase

Question 13

What is the main function of the pentose phosphate pathway (PPP)?

Accepted Answer

To provide NADPH and ribose-5-phosphate for biosynthesis

Question 14

Which of the following best explains why glycolysis and gluconeogenesis are reciprocally regulated?

Accepted Answer

To prevent futile cycles and maintain metabolic balance

Question 15

Which enzyme catalyzes the reversible conversion between dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (GAP) in glycolysis?

Accepted Answer

Triose phosphate isomerase

Question 16

A patient with a deficiency in glucose-6-phosphatase would have difficulty with which metabolic process?

Accepted Answer

Gluconeogenesis

Question 17

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

Accepted Answer

It involves the direct transfer of a phosphate group to ADP to form ATP

Question 18

Which enzyme is responsible for adding branches to the glycogen molecule during glycogen synthesis?

Accepted Answer

Amylo-(1,4-1,6)-transglycosylase (branching enzyme)

Question 19

Which of the following is a key allosteric activator of phosphofructokinase (PFK) in glycolysis?

Accepted Answer

AMP

Question 20

In the Cori cycle, what is the primary role of the liver?

Accepted Answer

To convert lactate to glucose

Glycolysis, Gluconeogenesis, and Glycogen Metabolism: Pathways and Regulation

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