Question

Muscle glycogen phosphorylase is regulated by both allosteric effectors, such as AMP and ATP, and by hormonal signaling. Allosteric effectors bind to the phosphorylated and unphosphorylated forms of the enzyme and shift the equilibrium between the inactive T conformation and the active R conformation. In contrast, hormonal regulation involves activation of kinase and phosphatase enzymes, which modulate the phosphorylation status of glycogen phosphorylase.

Which TWO statement(s) below best explain the metabolic logic of this dual regulatory mechanism?

Answer 1

Muscle glycogen phosphorylase is regulated by both allosteric effectors and hormonal signaling. Allosteric effectors can shift the equilibrium between inactive and active conformations of the enzyme, while hormonal signaling involves the phosphorylation status of the enzyme.

Step-by-step explanation:

Regulation of muscle glycogen phosphorylase involves both allosteric effectors and hormonal signaling. Allosteric effectors such as AMP and ATP can bind to the phosphorylated and unphosphorylated forms of the enzyme, shifting the equilibrium between the inactive T conformation and the active R conformation. This allows for quick and reversible regulation of the enzyme's activity. On the other hand, hormonal regulation involves the activation of kinase and phosphatase enzymes, which modulate the phosphorylation status of glycogen phosphorylase. When activated, these enzymes can either phosphorylate or dephosphorylate the enzyme, leading to its activation or inhibition, respectively.