LIFE 210 Lecture Notes - Fructose, Gluconeogenesis, Glucokinase
Document Summary
Regulated hetereoallosterically by p, p2 or purely regulatory molecules. Have bypass reactions at key regulated steps catalyzed by different enzymes. Avoid futile cycles (catabolic and anabolic pathways running at the same rate, just using up energy) Takes about twice as much atp to produce glucose than to break it down. Amp used as effector indicative of low energy charge. Glucokinase is inhibited by g6p & f6p in glycolysis. Amp and fructose 2,6 bisp activate p-fructokinase in glycolysis; atp inhibits. Amp and fructose 2,6 bisp inhibit f1,6 bisphosphatase in gluconeogenesis. Atp and acetyl-coa inhibit pyruvate kinase in glycolysis; f1,6 bisp activates. Role of fructose 2,6 bisp in liver cell metabolism. The liver produces glucose for the brain, muscles, etc. Regulates phosphofructokinase-1 (pfk-1) and fructose 1,6 bisphosphatase (f1,6 bisptse) allosterically (step 3 bypass reactions) The enzyme is phosphorylated by camp dependent kinase (pka) Glucagen in the blood regulates camp production in liver cells.
