Saturday, January 3, 2009
Energy generation in the mitochondrion, part 2
source of image: www.britannica.com
As mentioned in yesterday’s post, the next 2 phases of energy generation in cells are Krebs’ cycle and oxidative phosphorylation.
Krebs’ cycle is also known as citric acid cycle because the first substrate formed is citric acid. This process occurs in the matrix of the mitochondrion.
This cycle is an 8-step process that changes AcetylCoA to citric acid and the latter into oxaloacetate. Main products of this cycle are Hydrogen ions and electrons which are immediately received by Hydrogen acceptors and transferred to the last phase or oxidative phosphorylation. By-products of this cycle are CO2 and H2O.
Only 2 ATPs are actually produced in the Krebs’cycle itself. However, since it is coupled with the last phase, oxidative phosphorylation, 22 more ATPs are produced through the coupled reactions.
We will talk about the last phase of this energy generation in tomorrow’s post.