Electron Transport Stage??

[saheh]

can anyone expplain what exactly happens?
Im a little confused as to how the ATP are produced from the energy given off, and the proton gradient and all :/

thanks!

[paulsterio]

First of all, you will have the loaded electron carriers NADH and FADH2, which are obtained from the Citric Acid Cycle (also known as Kreb's or TCA Cycle).

Now, the electron transport chain, is basically a series of enzymes which remove the H+ from these carriers and generate energy.

First, the Protons are removed from NADH and FADH2 by their respective enzymes (I don't think you need to know the name) - the protons are then ejected between the two layers of the mitochondrial matrix. At this stage, as there is a build up of protons, there will be a charge gradient. This means that the protons want to move back in order to neutralise the charge. However, they cannot pass through the lipid layer by simple diffusion, thus, this is where ATP synthase comes in.

ATP synthase couples the moving of protons back into the mitochondria with the production of ATP from ADP and Pi.