Glycogenolysis Regulation PDF
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Summary
This document explains the regulation of glycogenolysis. It details the role of enzymes like glycogen phosphorylase and how hormones like adrenaline and glucagon influence the process. The document also explains how calcium plays a role in muscle contraction and glycogen breakdown.
Full Transcript
Glycogenolysis regulation Liver has an enzyme called glucose 6-phosphatase wich turns glucose 6-phosphate into glucose when needed by the body Glycogen in muscles is broken down for anaerobic glycolysis. Glucose 6-phosphate enters glycolysis and turns into pyruvate which turns into lactate and feeds...
Glycogenolysis regulation Liver has an enzyme called glucose 6-phosphatase wich turns glucose 6-phosphate into glucose when needed by the body Glycogen in muscles is broken down for anaerobic glycolysis. Glucose 6-phosphate enters glycolysis and turns into pyruvate which turns into lactate and feeds into gluconeogenesis The regulation occurs by Glycogen phosphorylase Liver has phosphorylase a (active). Inactivated by Glucose. - Muscles has phosphorylase b (inactive). Activated by AMP and inhibited by ATP Therefore turned on by High AMP, low ATP High Ca2+ High adrenaline High glucagon Hormonal regulation- triggers the conversion from b to a (inactive to active form) Adrenaline/ Epinephrine from adrenal galnds and glucagon from panreatic alpha cells Adenylate cyclase GPCR ATP Phosphorylase kinase can also be activated by Ca2+ in muscles Has 4 subunits (alpha, beta delta and gamma) The delta subunit is calmodulin- Ca2+ sensor When Ca2+ released during muscle contraction, stimulates glycogen breakdown as it activates phosphorylase a. CAMP PKA Phosphorylase kinase (phosphorylates) Turning off the signal, dephosphorylase the phosphorlyase a to b by protein phosphatase 1 or Abscence of activated phosphorylase kinase that phosphorylates b to a Inactive from b to active form a
