What role does insulin play in glycogen metabolism?

Insulin plays a crucial role in glycogen metabolism, particularly in promoting the storage of glucose as glycogen in the liver and muscle cells. When insulin is released in response to elevated blood glucose levels, it stimulates the process of glycogenesis, which is the formation of glycogen from glucose.

One of the key actions of insulin is to activate glycogen synthase, the enzyme responsible for converting glucose into glycogen. This activation facilitates the storage of excess glucose, effectively lowering blood sugar levels.

Additionally, insulin inhibits glycogen phosphorylase, the enzyme responsible for breaking down glycogen into glucose. By inhibiting this enzyme, insulin prevents the release of glucose into the bloodstream, promoting instead the storage of glucose as glycogen.

Therefore, the correct answer encompasses both the activation of glycogen synthase and the inhibition of glycogen phosphorylase, illustrating the dual function of insulin in facilitating glycogen synthesis while preventing glycogen breakdown. This coordinated action is essential for maintaining glucose homeostasis, allowing the body to manage energy storage and availability efficiently.