GLUCONEOGENESIS

GLUCONEOGENESIS tissues reliant upon glucose - neural - RBC - kidney - testes factors leading to its activation - fasting - diabetes - low CHO diet - prolonged exercise new glucose largely made from protein; some from glycerol all blood glucose goes through the liver - dietary - glycogenic - gluconeogenic (kidney also) glucogenic substance: converted to glucose detected in urine after PHLORIZIN treatment (lowers renal threshold for glucose) enzymes: glucose 6 phosphatase (ER membrane, faces lumen) FBPase (cytosol) PEP carboxykinase (cytosol) Pyruvate Carboxylase (mito matrix) requires 4 ATP, 2GTP to go from 2 pyruvate  glucose Pyruvate  PEP mito: PC pyruvate + HC03  OAA Acetyl CoA: allosteric activator present in high quantities during FATTY ACID OXIDATION requires ATP  ADP involves biotin-carboxy intermediate; “ping pong rxn” flips between BC (biotin carboxylase site) and CT (carboxyl transferase) cyto: PEPCK OAA + GTP  PEP + CO2 + GDP OAA decarboxylated, phosphorylated txnally regulated cAMP, glucocoriticoid activates txn insulin inhibits txn Mobilization of Muscle Protein: protease: cleaves into individual aa’s transamination: aa’s  a-keto acids consolidation of all into GLN, ALA REGULATION events leading to gluconeogenesis caused by fasting 1. glycogen depleted