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.
- Each acetylCoA (2C) combines with an oxaloacetic acid (4C) to make a 6C compound (citric acid).
- 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.
- 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 acetylCoA||2 oxaloacetate|
|6 NAD||6 reduced NAD (6 NADH + H+)|
|2 FAD||2 reduced FAD (2 FADH + H+)|
|2 ADP + P||2 ATP|