Classify each action based on whether it increases or decreases the activity of glycogen synthase. Increases glycogen synthase activity glucose binding to glycogen phosphorylase binding of cyclic AMP to protein kinase (PKA) binding of epinephrine to the -adrenergic receptor Answer Bank Decreases glycogen synthase activity release of protein phosphatase 1 (PP1) from glycogen phosphorylase phosphorylation of glycogen synthase phosphorylation of glycogen synthase kinase insulin secretion