Oxidative phosphorylation

I. Chemiosmotic coupling hypothesis

• Peter Mitchell
• Movement of H+ across inner membrane produces gradient

II. Proton motive force

• Two components
  • membrane potential
  • pH gradient
• Calculate gradient using equation
  • pH gradient 1.4 units in liver and E. coli
• 10 H+ pumped out/ pair of electrons

III. Production of ATP

• ATP synthetase in inner membrane
• Two components
  • Fo in membrane
  • F1 stalk, matrix of mitochondria
• 2.5 ATP/NADH
• 1.5 ATP/FADH
• P/O ratios
• How much ATP?
  • Pyruvate to Acetyl CoA
  • TCA cycle
• NADH from Glycolysis
  • Malate-aspartate shuttle
  • phosphoglycerate shuttle
• Total ATP
  • glycolysis and TCA cycle
  • efficiency compared to just glycolysis
• Transport of ATP
  • ATP/ADP exchange
  • Pi/OH- exchange

IV. Rates of Respiration

• O2 consumption versus time
• Addition of ADP needed
• calculate P/O ratio of different compounds
• Uncouplers and their effect
  • DNP
  • vallinomycin
  • gramicidin