The video tutorial explains the control of glycogen metabolism, focusing on the enzymes glycogen phosphorylase and glycogen synthase. Glycogen phosphorylase is activated by phosphorylation through phosphorylase kinase, which is stimulated by glucagon and epinephrine. In contrast, glycogen synthase is activated by dephosphorylation, promoted by insulin. The tutorial highlights the opposing regulation mechanisms of these enzymes, emphasizing the role of kinases and phosphatases in their activity.

Which enzyme is responsible for breaking down glycogen into glucose 1 phosphate?

• Glycogen phosphorylase

• Protein kinase A

• Phosphorylase kinase

• Glycogen synthase

What activates glycogen phosphorylase?

• Dephosphorylation

• Insulin

• Protein phosphatase

• Phosphorylation

Which signaling molecules increase cyclic AMP to activate phosphorylase kinase?

• Glucagon and epinephrine

• Epinephrine and insulin

• Cyclic AMP and insulin

• Insulin and glucagon

How is glycogen synthase activated?

• By cyclic AMP

• By phosphorylation

• By glucagon

• By dephosphorylation

What role does insulin play in glycogen metabolism?

• Activates protein phosphatases

• Increases cyclic AMP

• Phosphorylates glycogen synthase

• Activates glycogen phosphorylase