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Glycogenesis: The Synthesis of Glycogen

Description: Glycogenesis is the process by which glucose is converted into glycogen for storage in the liver and muscles. This quiz will test your knowledge of the steps involved in glycogenesis and the enzymes that catalyze these reactions.
Number of Questions: 15
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Tags: glycogenesis glycogen synthesis glucose metabolism
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Which enzyme is responsible for the initial phosphorylation of glucose in glycogenesis?

  1. hexokinase

  2. glucokinase

  3. phosphofructokinase

  4. pyruvate kinase


Correct Option: B
Explanation:

Glucokinase is the enzyme that catalyzes the phosphorylation of glucose to glucose-6-phosphate, the first step in glycogenesis.

What is the role of glucose-6-phosphate isomerase in glycogenesis?

  1. converts glucose-6-phosphate to fructose-6-phosphate

  2. converts fructose-6-phosphate to glucose-6-phosphate

  3. converts fructose-1,6-bisphosphate to glucose-1,6-bisphosphate

  4. converts glucose-1-phosphate to glucose-6-phosphate


Correct Option: A
Explanation:

Glucose-6-phosphate isomerase catalyzes the isomerization of glucose-6-phosphate to fructose-6-phosphate.

Which enzyme catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate?

  1. phosphofructokinase

  2. fructose-1,6-bisphosphatase

  3. aldolase

  4. triose phosphate isomerase


Correct Option: A
Explanation:

Phosphofructokinase catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate.

What is the role of aldolase in glycogenesis?

  1. converts fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate

  2. converts dihydroxyacetone phosphate and glyceraldehyde-3-phosphate to fructose-1,6-bisphosphate

  3. converts glucose-6-phosphate to fructose-6-phosphate

  4. converts glucose-1-phosphate to glucose-6-phosphate


Correct Option: A
Explanation:

Aldolase catalyzes the cleavage of fructose-1,6-bisphosphate into dihydroxyacetone phosphate and glyceraldehyde-3-phosphate.

Which enzyme catalyzes the isomerization of dihydroxyacetone phosphate to glyceraldehyde-3-phosphate?

  1. triose phosphate isomerase

  2. aldolase

  3. glyceraldehyde-3-phosphate dehydrogenase

  4. phosphoglycerate kinase


Correct Option: A
Explanation:

Triose phosphate isomerase catalyzes the isomerization of dihydroxyacetone phosphate to glyceraldehyde-3-phosphate.

What is the role of glyceraldehyde-3-phosphate dehydrogenase in glycogenesis?

  1. converts glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate

  2. converts 1,3-bisphosphoglycerate to glyceraldehyde-3-phosphate

  3. converts dihydroxyacetone phosphate to glyceraldehyde-3-phosphate

  4. converts fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate


Correct Option: A
Explanation:

Glyceraldehyde-3-phosphate dehydrogenase catalyzes the oxidation of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate.

Which enzyme catalyzes the phosphorylation of 1,3-bisphosphoglycerate to 3-phosphoglycerate?

  1. phosphoglycerate kinase

  2. glyceraldehyde-3-phosphate dehydrogenase

  3. triose phosphate isomerase

  4. aldolase


Correct Option: A
Explanation:

Phosphoglycerate kinase catalyzes the phosphorylation of 1,3-bisphosphoglycerate to 3-phosphoglycerate.

What is the role of phosphoglycerate mutase in glycogenesis?

  1. converts 3-phosphoglycerate to 2-phosphoglycerate

  2. converts 2-phosphoglycerate to 3-phosphoglycerate

  3. converts phosphoenolpyruvate to pyruvate

  4. converts pyruvate to phosphoenolpyruvate


Correct Option: A
Explanation:

Phosphoglycerate mutase catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate.

Which enzyme catalyzes the dehydration of 2-phosphoglycerate to phosphoenolpyruvate?

  1. enolase

  2. phosphoglycerate kinase

  3. phosphoglycerate mutase

  4. glyceraldehyde-3-phosphate dehydrogenase


Correct Option: A
Explanation:

Enolase catalyzes the dehydration of 2-phosphoglycerate to phosphoenolpyruvate.

What is the role of pyruvate kinase in glycogenesis?

  1. converts phosphoenolpyruvate to pyruvate

  2. converts pyruvate to phosphoenolpyruvate

  3. converts glucose-6-phosphate to fructose-6-phosphate

  4. converts fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate


Correct Option: A
Explanation:

Pyruvate kinase catalyzes the conversion of phosphoenolpyruvate to pyruvate.

Which enzyme catalyzes the transfer of the glycosyl unit from UDP-glucose to glycogen?

  1. glycogen synthase

  2. glycogen phosphorylase

  3. glycogen branching enzyme

  4. glycogen debranching enzyme


Correct Option: A
Explanation:

Glycogen synthase catalyzes the transfer of the glycosyl unit from UDP-glucose to glycogen.

What is the role of glycogen branching enzyme in glycogenesis?

  1. creates branch points in the glycogen molecule

  2. removes branch points from the glycogen molecule

  3. transfers the glycosyl unit from UDP-glucose to glycogen

  4. converts glucose-6-phosphate to fructose-6-phosphate


Correct Option: A
Explanation:

Glycogen branching enzyme creates branch points in the glycogen molecule.

Which enzyme catalyzes the removal of branch points from the glycogen molecule?

  1. glycogen debranching enzyme

  2. glycogen branching enzyme

  3. glycogen synthase

  4. glycogen phosphorylase


Correct Option: A
Explanation:

Glycogen debranching enzyme catalyzes the removal of branch points from the glycogen molecule.

What is the role of glycogen phosphorylase in glycogenesis?

  1. catalyzes the breakdown of glycogen to glucose-1-phosphate

  2. catalyzes the synthesis of glycogen from glucose-1-phosphate

  3. creates branch points in the glycogen molecule

  4. removes branch points from the glycogen molecule


Correct Option: A
Explanation:

Glycogen phosphorylase catalyzes the breakdown of glycogen to glucose-1-phosphate.

Which hormone stimulates the breakdown of glycogen to glucose-1-phosphate?

  1. glucagon

  2. insulin

  3. epinephrine

  4. growth hormone


Correct Option: A
Explanation:

Glucagon stimulates the breakdown of glycogen to glucose-1-phosphate.

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