3. krebs cycle

• overview

  • occurs in matrix of mitochondria
  • happens once for every acetyl CoA molecule- happens twice for every glucose molecule
• first step

  • acetyl CoA(2c) combines with oxaloacetate(4c) to form citrate(6c)
  • co enzyme A leaves and goes back to link reaction
• second step

  6c citrate converted to 5c molecule

  • decarboxylation occurs- C02 is removed
  • dehydrogenation/oxidation also occurs- hydrogen removed from citrate
  • hydrogen removed used to produce NADH(reduced NAD)
• third step


  5c molecule converted to 4c molecule(oxaloacetate)

  • decarboxylation and dehydrogenation occur- producing 1 reduced FAD molecule and 2 reduced NAD molecules
  • 1 ATP molecule produced
  • 5c molecule converted to oxaloacetate(4c)
• products

  • after 2 cycles for 2 acetyl CoA molecules
  • 4 C02 leave
  • 6 NADH
  • 2 FADH
  • 2 ATP