Krebs Cycle

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Krebs Cycle

This is also known as the citric acid cycle or the tricarboxylic acid cycle.

For each glucose molecule, there were 2 pyruvic acid molecules formed, (and therefore 2 acetylCoA molecules formed) so the whole cycle takes place twice for every glucose molecule respired.

Krebs Cycle
  1. Each acetylCoA (2C) combines with an oxaloacetic acid (4C) to make a 6C compound (citric acid).

  2. In a series of steps, for each 6C compound,
    2 CO2 molecules are released,
    3 NAD molecules are reduced,
    1 FAD molecule is reduced,
    1 ATP molecule is made directly.

  3. The 4C compound is regenerated (by the removal of the 2 Cs in 2 CO2 molecules) so that the cycle can begin again with more molecules of acetylCoA.

Into Krebs:Out of Krebs:
2 acetylCoA2 oxaloacetate
h4 CO2
6 NAD6 reduced NAD (6 NADH + H+)
2 FAD2 reduced FAD (2 FADH + H+)
2 ADP + P2 ATP