1 SURVEY OF BIOCHEMISTRY Glycogen

2 2 Ways To Generate Glucose GlycogenolysisGluconeogenesis Break down of glycogen Glucose Glucose 1-Phosphate Glucose 6-Phosphate Synthesis of glucose from non-carb precursors Lactate Pyruvate

3 Energetics of Reversing Glycolysis Glucose Pyruvate Hexokinase ∆G° = -17 kJ/mol Phosphofructokinase ∆G° = -14 kJ/mol Pyruvate Kinase ∆G° = -31 kJ/mol Reversing glycolysis is not energetically feasible! Ref: Rodney Boyer Interactive Concepts in Biochemistry

4 Pyruvate to Phosphoenolpyruvate Dilemma: Oxaloacetate can only be generated from pyruvate in the mitochondria Pyruvate gets synthesized initially in the cytosol

5 PEP and Oxaloacetate Transport Fig does not show pyruvate! Draw another view of this process that may be more helpful

6 Gluconeogenesis

7 Energetics Revisited ∆G value comparisons By what mechanisms do these enzymes work?

8 Pyruvate Carboxylase Cofactor

9 Enzyme-Cofactor Complex

10 Pyruvate Carboxylase

11 Pyruvate Carboxylase

12 PEPCK Mechanism

13 Ch. 16 Overview 16-1Glycogen Breakdown (Fri) 16-2Glycogen Synthesis (Wed) 16-3Control of Glycogen Metabolism (Wed) 16-4Gluconeogenesis (Mon)

14 Enzymes in Glycogen Synthesis UDP-Glucose Pyrophosphorylase Glycogen Synthase Glycogen Branching Enzyme

15 UDP-Glucose Pyrophosphorylase activates glucosyl units PP i

16 Glycogen Synthase

17 Glycogen Branching Enzyme

18 Overview

19 PRS Which of the following enzymes is involved in gluconeogenesis? 1.Pyruvate carboxylase 2.Pyruvate kinase 3.Phosphofructokinase 4.Glycogen synthase

20 PRS Which of the following is not a product of glycolysis? 1.Pyruvate 2.Fructose 1,6-Bisphosphate 3.Oxaloacetate 4.Glucose 6-Phosphate

21 PRS Which enzyme produces glucose 1- phosphate? 1.Hexokinase 2.Glycogen Debranching Enzyme 3.Glycoen Branching Enzyme 4.Glycogen Phosphorylase