Regulation of Glucose metabolism by Cell's Internal Condition
Low ATP demand (High Concetration)	High ATP demand (Low Concetration)
Enzymes involved in regulation of glucose metabolism: GS= Glycogen Synthase GP= Glycogen Phosphorylase PFK-1 = PhosphoFructoKinase FBPase = Fructose 1,6 BisPhosphatase PDH = Pyruvate DeHydrogenase Compounds OTHER THAN ATP/AMP that have an allosteric effect on enzyme activities are listed near the form of the enzyme that they bind to preferentially. eg citrate induces the POOR catalytic form of PFK-1 and is listed near the Least Active form of the enzyme. For cells that store glycogen as well as consume glucose (Liver and Muscle cells), the system responds to changes in [ATP] within the cell as pictured above. In times of low demand the [ATP] is high relative to the [AMP]---- gluconeogenesis and glycogen synthesis are favored by making PFK-1 and GP less active while increasing the activity of GS and FBPase through allosteric mechanisms. PDH is covalently phosphorylated and incativated by a specific kinase under these conditions as well. In times of high ATP demand it's concentration drops relative to [AMP] ---- glycogen breakdown and glycolysis are favored by allosteric mechanisms. The effects are the opposite of that mentioned above. PDH is also more active by a specific phosphorylase the hydrolyzes phosphate.