Overall Reaction Glc + 2NAD+ + 2ADP + 2Pi Aerobic Glc + 2NAD+ + 2ADP + 2Pi 2 pyruvate + 2NADH + 2H+ + 2ATP + 2H2O Glc + 2ADP + 2Pi 2 Lactate + 2ATP + 2H2O Anaerobic

Mg+2 or glucokinase Reactions Mg+2

Comparison of Glucokinase & Hexokinase 1. Liver (& pancreas) Only Extrahepatic cells (All Cells) 2. Specific for Glc Non-specific (all hexoses) 3. Km high, low affinity for Glc Km low, high affinity for Glc 4. Not inhibited by G-6-P Allosteric inhibition by G-6-P

Comparison of Glucokinase & Hexokinase 5. Inducible enzyme;  in fasting and diabetes,  in fed state and by insulin Non-inducible, Not very much influenced by fasting, feeding, diabetic state or insulin level 6. Main function is to clear glucose from blood after meals Main function is to make glucose available to tissues at low glucose conc. in blood (during fasting or starvation)

Reactions Glc-6-phosphate  Glycolysis Glycogenesis HMP Shunt Mg+2 or glucokinase Reactions Glc-6-phosphate  Glycolysis Glycogenesis HMP Shunt Uronic Acid Pathway Mg+2

Reactions

Reactions 1,3 Bisphosphoglycerate & Phosphoenolpyruvate are ADP ATP Reactions 1,3 Bisphosphoglycerate & Phosphoenolpyruvate are Super high energy compounds Substrate level phosphorylation ADP ATP

Reactions

Glycolysis - Summary Glucose Glucose 2 Lactate 2 Pyruvate 2 ATP 4 ADP 2 NAD 2 NADH + H 4 ADP Glucose 2 Lactate 2 ATP 2 ADP 4 ATP

Bioenergetics AEROBIC GLYCOLYSIS 2NADH + H+ = 2 x 3ATP = 6 ATP Substrate Level = 2 x 2 ATP = 4 ATP ____________________________________________ TOTAL = 10 ATP Consumed = -2 ATP Net Balance = 8 ATP

Bioenergetics ANAEROBIC GLYCOLYSIS (e.g. RBC) Substrate Level = 4 ATP Consumed = -2 ATP ____________________________ Net Balance = 2 ATP RBCs (only when first site of ATP generation is bypassed) Substrate Level = 2 ATP Consumed = -2 ATP Net Balance = 0 ATP

This metabolite(2,3-BPG) combines with Hb, causing a decrease in its affinity for O2, favouring the unloading of O2 even at low O2 pressure.