<prompt> A 15-year-old type I diabetic faints after injecting himself with insulin. He is administered Glucagon and rapidly recovers consciousness. Glucagon induces activity of:Glycogen synthaseGlycogen phosphorylaseGlucokinaseHexokinase  <response>: Glucagon catabolic hormone activates the Rate limiting enzyme of glycogenolysis catabolic pathway i.e. Glycogen phosphorylase. ADDITIONAL EDGE: Fig.: In fasting state, Glucagon hormone is released. Regulation of glycogen metabolism at the level of glycogen phosphorylase: cAMP activates phosphorylase kinase by a cAMP-dependent protein kinase, which in turn activates glycogen phosphorylase. Calcium activates the calmodulin component of phosphorylase kinase directly, which in turn activates glycogen phosphorylase. 5 AMP acts allosterically to activate glycogen phosphorylase. Protein phosphatase-1 inactivates glycogen phosphorylase. 