Question

Glycogenolysis and glycogen synthesis are regulated in such a way that neither process is active at the same time. During the fasted state, (ratio of insulin to glucagon is low) which of the following best characterizes the regulation of these pathways?
a. Both glycogen phosphorylase and glycogen synthase are phosphorylated

b. Both glycogen phosphorylase and glycogen synthase are dephosphorylated

c. Glycogen phosphorylase is phosphorylated and glycogen synthase is dephosphorylated

d. Glycogen phosphorylase is dephosphorylated and glycogen synthase is phosphorylated

Answer 1

Answer:

a. Both glycogen phosphorylase and glycogen synthase are phosphorylated

Explanation:

Glycogenesis is the process of glycogen synthesis while glycogenolysis is the process of glycogen breakdown.

They both hold a reciprocal relationship between them and the factors which enhance the rate of one, inhibit the other.

The main forms of the control is varied phosphorylation of the enzyme, glycogen synthase and enzyme, glycogen phosphorylase by the protein kinase A .

On phosphorylation, Phosphorylated glycogen synthase is inactive while glycogen phosphorylase is activate.

During fast state, glucose is required by the body which is provided by the process of glycogenolysis and thus phosphorylation will help to regulate the process.