Chemiosmotic Theory pt 2

Hey so I am back again. To finally do what I want to do. Talk about inhibition! Okay maybe this is weird that I like talking about inhibition. However lets go on with the explanations:

There are three substances which affect the electron transport system; cyanide, 2,4-DNP and rotenone. So we will leave the best for last. Cyanide and Rotenone can be grouped as they both work by inhibiting one of the four complex in the inner membrane. While 2,4-DMP is an example of an uncoupler.

2,4-DMP separates one of the processes from the other. Therefore one process happens in the absence of the other. Whether it is that the complex transport protons from the matrix to the inter-membrane or the ATP synthase transporting protons from the inter-membrane to the matrix. All the uncouplers are hyhdrophobic and have the ability to release protons. 2,4-DMP binds the protons on one side of a membrane and drifts to the opposite side of the membrane where it will release the proton. Because of this it is impossible to maintain a proton gradient and hence inhibits the ETC.

Cyanide is a very toxic substance. Cyanide inhibits complex IV (cytochrome c oxidase) of the ETC. Cyanide prevents the transport of the electrons from the matrix to the inter-membrane space.

Rotenone is a competitive inhibitor and inhibits complex I. Rotenone inhibits the transfer of the electrons from the iron sulfur centers in complex I. This can interfere with NADH during the creation of ATP.

Please note that neither Cyanide or Rotenone interferes with ATP synthase. Also once one complex is inhibited it affects all the other complexes.

So enjoy people!