Lecture 305: regulation Flashcards
ATP activates/ deactivates
- activates = gluconeogenesis
- deactivates = glycolysis
insulin activates/ deactivates
- activates = glycolysis
- deactivates = gluconeogenesis
glucagon activates/ deactivates
- activates = gluconeogenesis
- deactivates = glycolysis
regulation of hexokinase
- controlled by feedback inhibition of G6P
regulation of glucokinase
- regulated by substrate = amount of glucose present
- cytosolic enzyme
regulation of G6Pase
- controlled by substrate = amount of G6P present
activity of glucokinase and G6Pase depends on
- concentration of glucose and G6P [whichever is higher]
PFK-1 de/ activated by
- activated by = AMP and F26BP
- deactivated by cAMP = activates protein kinase A which activates F26BPase
function of F26BPase
- chops up F26BP = decreases activity of PFK-1 and inhibition of F16BPase
F16BPase de/activated by
- activated = cAMP
- deactivated = AMP and F26BP
when insulin activates a protein [glycolysis]
- protein activates protein phosphatase A = activates PFK-2 = synthesizes F26BP = activates PFK-1 and inhibits F16BPase
when glucagon degrades F26BP, PFK-1 is ___
- unbound and can be attacked by ATP/ citrate
regulation of pyruvate kinase
- feedforward activation by F16BP and feedback inhibition by ATP
pyruvate kinase de/activated by
- activated = insulin
- deactivated = glucagon
pyruvate carboxylase activated by
- acetyl-CoA
PEPCK de/activated by
- activated by = glucagon
- deactivated = insulin
glucagon (de/activates) cAMP in glycogenolysis
- glucagon activates cAMP = protein kinase A = phosphorylase b kinase = glycogen phosphorylase a = glycogen breakdown = glucose
how insulin stops glycogenolysis
- stops cAMP production = inactivates adenylate kinase and starts its own cascade = activates PP1 = inactivates phosphorylase b kinase and glycogen phosphorylase
insulin activation in glycogenesis
- PP1 activates glycogen synthase
inactivates glycogen synthase
protein kinase A
