Glycogenolysis + regulation

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What is the enzyme responsible for adding orthophosphate to cleave glycogen?

Glycogen Phosphorylase (correct)

Glycogen 1-phosphorylase

Phosphoglucomutase

Debranching enzyme

Which enzyme is involved in attacking the a-1,4 linkages during glycogenolysis?

Glycogen 1-phosphorylase (correct)

Phosphoglucomutase

Glycogen Phosphorylase

Debranching enzyme

What is the role of debranching enzymes in glycogenolysis?

Cleaving glycogen with orthophosphate

Converting glucose 1-phosphate to glucose 6-phosphate

Transferring glucose residues from a-1,6 to a-1,4 linkages (correct)

Attacking a-1,4 linkages

What is the final product formed after the removal of the glucose molecule from the a-1,6 linkage?

Glucose 1-phosphate Signup and view all the answers

Which enzyme is responsible for converting glucose 1-phosphate into glucose 6-phosphate?

Phosphoglucomutase Signup and view all the answers

Explain the role of Glycogen Phosphorylase in glycogenolysis.

Catalyzes the cleavage of glucose from glycogen by adding orthophosphate. Signup and view all the answers

What is the function of Glycogen 1-Phosphorylase in glycogenolysis?

Attacks the a-1,4 linkages in glycogen until it reaches the a-1,6 linkages. Signup and view all the answers

Describe the mechanism of action of debranching enzymes in glycogenolysis.

Transfers 3 glucosyl residues from the a-1,6 linkage to the a-1,4 linkage and hydrolyzes the final glucose molecule. Signup and view all the answers

How does phosphoglucomutase participate in glycogenolysis?

Converts glucose 1-phosphate into glucose 6-phosphate. Signup and view all the answers

Explain the significance of glucose 6-phosphate in glycogenolysis.

Can be directly metabolized and is an essential intermediate in glucose metabolism. Signup and view all the answers

What enzyme in the liver is responsible for converting glucose 6-phosphate into glucose when needed by the body?

Glucose 6-phosphatase Signup and view all the answers

How is Glycogen broken down in muscles for anaerobic glycolysis?

Glycogen phosphorylase Signup and view all the answers

What activates phosphorylase b in muscles and inhibits phosphorylase a?

AMP activates phosphorylase b, while ATP inhibits it. Signup and view all the answers

Which hormone triggers the conversion of phosphorylase from its inactive form (b) to the active form (a)?

Adrenaline/Epinephrine and glucagon Signup and view all the answers

What is the role of Ca2+ in the regulation of glycogen breakdown in muscles?

Ca2+ activates phosphorylase a, stimulating glycogen breakdown. Signup and view all the answers

How is the signal for glycogen breakdown turned off in muscles?

By dephosphorylating phosphorylase a to b. Signup and view all the answers

What triggers the conversion of phosphorylase b to a in muscles?

High Ca2+ levels Signup and view all the answers

Which subunit of phosphorylase kinase acts as the Ca2+ sensor?

Delta Signup and view all the answers

What inhibits phosphorylase a in muscles?

Low ATP Signup and view all the answers

Which hormone triggers the conversion of phosphorylase b to a?

Epinephrine Signup and view all the answers

What role does protein phosphatase 1 play in glycogen breakdown regulation?

Converts phosphorylase a to b Signup and view all the answers

In muscles, what activates phosphorylase kinase besides Ca2+?

AMP Signup and view all the answers

What is the main factor that turns on phosphorylase b to a in muscles?

Low ATP and High AMP levels Signup and view all the answers

What activates phosphorylase kinase by binding to the GPCR?

Cyclic AMP (cAMP) Signup and view all the answers