Glycogenesis, Glycogenolysis, and HMP Shunt

1. Which enzyme is primarily responsible for the synthesis of glycogen from glucose?

• Glucose-6-phosphate dehydrogenase

• Glycogen phosphorylase

• Hexokinase

• Glycogen synthase

2. Assertion: Glycogen phosphorylase is activated during fasting. Reason: It promotes glycogenolysis to release glucose. Is the assertion true and is the reason a correct explanation?

• It promotes gluconeogenesis instead of glycogenolysis.

• Yes, both the assertion and reason are true, and the reason is a correct explanation.

• Glycogen phosphorylase is inhibited during fasting.

• The assertion is false, but the reason is true.

3. What is the primary function of the HMP shunt pathway?

• To generate NADPH and ribose-5-phosphate.

• To produce ATP and glucose.

• To synthesize fatty acids and cholesterol.

• To break down amino acids and produce urea.

4. Assertion: Glycogen synthase is active when dephosphorylated. Reason: Insulin promotes the dephosphorylation of glycogen synthase. Is the assertion true and is the reason a correct explanation?

• False, glycogen synthase is active when phosphorylated.

• True, the reason is a correct explanation.

• False, the reason is not a correct explanation.

• True, but the reason is incorrect.

5. Which of the following is a product of the HMP shunt pathway?

• NADPH

• ATP

• Acetyl-CoA

• FADH2

6. During glycogenesis, which molecule serves as the primer for glycogen synthesis?

• Glycogen synthase

• Glycogenin

• Fructose-1,6-bisphosphate

• Glucose-6-phosphate

7. Assertion: Glycogenolysis occurs in the liver and muscle. Reason: Both tissues store glycogen for energy. Is the assertion true and is the reason a correct explanation?

• Both tissues do not store glycogen.

• Glycogenolysis only occurs in the liver.

• The assertion is false and the reason is correct.

• True; Reason is not a correct explanation.

8. What role does glucose-6-phosphate play in the regulation of glycogenesis?

• Glucose-6-phosphate promotes glycogenolysis instead of glycogenesis.

• Glucose-6-phosphate promotes glycogenesis by activating glycogen synthase.

• Glucose-6-phosphate has no effect on glycogenesis.

• Glucose-6-phosphate inhibits glycogenesis by deactivating glycogen synthase.

9. Which enzyme is inhibited by high levels of ATP during glycogenolysis?

• glycogen synthase

• phosphofructokinase

• hexokinase

• glycogen phosphorylase

10. Assertion: The HMP shunt pathway generates NADPH. Reason: NADPH is used for fatty acid synthesis. Is the assertion true and is the reason a correct explanation?

• NADPH is primarily used for DNA replication.

• The HMP shunt pathway generates ATP.

• Yes, both the assertion and reason are true, and the reason is a correct explanation.

• The HMP shunt pathway does not produce any metabolites.