Final answer:
Protein phosphatase-1 (PP1) deactivates glycogen phosphorylase by dephosphorylating it, converting the enzyme to a less active form and regulating glucose production during glycogenolysis.
Step-by-step explanation:
The enzyme responsible for deactivating glycogen phosphorylase (GP) is protein phosphatase-1 (PP1). This enzyme catalyzes the dephosphorylation of GP, converting it from its active form (a form) to its less active b form.
During the process of glycogenolysis, glycogen phosphorylase is a key enzyme that breaks down glycogen into glucose-1-phosphate. Hormones such as epinephrine and glucagon facilitate the phosphorylation and activation of glycogen phosphorylase through a signaling pathway that involves the conversion of ATP to cyclic AMP (cAMP), activation of protein kinase A (PKA), and subsequent activation of glycogen phosphorylase kinase (GPK).
Protein phosphatase-1 (PP1) plays a significant role in reversing this process by removing the phosphate group, hence deactivating glycogen phosphorylase and slowing down glycogen breakdown, ensuring that glucose production is regulated according to the cellular energy needs.