Question

Identify all the true statements. In the liver, stimulation of the glucagon receptor leads to activation of glycogen phosphorylase. activation of insulin receptor kinase. activation of PKA (cAMP‑dependent protein kinase). conversion of ATP to cAMP. activation of fructose 1,6‑bisphosphatase (FBPase‑1). activation of phosphofructokinase‑2 (PFK‑2).

Answer 1

Answer:

-activation of glycogen phosphorylase

-activation of PKA (cAMP‑dependent protein kinase)

-conversion of ATP to cAMP

-activation of fructose 1,6‑bisphosphatase (FBPase‑1)

Explanation:

The binding of glucagon to its receptors affects the production of glucose in the liver. Once the glucagon receptors are activated, it leads to the activation of adenylate cyclase in which in turn increases the levels of cAMP (cyclic AMP) conversion from ATP. The increased level of cAMP then activates PKA (protein kinase A). PKA results in the phosphorylation of pyruvate kinase which results to the activation of fructose 1,6‑bisphosphatase (FBPase‑1) which results to decrease in glycolysis.

Furthermore, PKA  activates phosphorylase kinase which results to the activation of glycogen phosphorylase and hence glycogenolysis. Glycogenolysis occurs when Glucose-1- phosphate is then released from glycogen. PKA also inhibits the action of glycogen synthase.