Glycolysis

Glycolysis

1. Stage 1

   • Requires 2 ATP
   • Traps and destabilises glucose
     • Forms 2x 3C

2. Stage 2

   • Generates 4 ATP
   • oxidises to pyruvate

3. Stage 1 Step 1

   • Trap glucose
     • Enters cells via facilitated diffusion
       • Through transporters
         • GLUT 3
           • Brain, nerve tissue
           • Low Km - constant uptake
         • GLUT 2
           • Liver, Beta cells in pancreas
           • High Km - proportional uptake
         • GLUT 4
           • Muscle and adipocytes
     • Phosphorylated
       • Negatively charged so cannot diffuse out
       • Hexokinase
         • induced fit model
         • feedback inhibition
         • Effectively irreversible
   • Stage 1 Step 2
     • Form Fructose 6-Phosphate
       • isomerisation
       • By enzyme phosphoglucose isomerase
     • Stage 1 Step 3
       • phosphorylation
         • Phosphofructokinase
           • sets the pace of glycolysis
           • inhibited by ATP, Citrate and H+ ions
           • Stimulated by AMP, ADP and fruc 2,6 bisphosphate