Question

What is reverse electron transport? What enzyme(s) are involved, and what is the essential action that takes place?

Answer 1

The reverse electron transport also known as the reverse electron flow is a mechanism in microbial metabolism.Chemolithotrops use an electron donor having higher redox potential than NADP+/NADPH,like nitrate or sulphur compounds which reduces NADP+ by using the energy.This energy is supplied by the consumption of proton motive forces which derive electrons in a reversible direction through an electron transport chain and thus,it is the reverse process of forward electron transport.Sometimes, the consumed energy during reverse electron transport is 5 times greater than energy gained during the forward process.Autrotrops use this energy to supply the reducing power for inorganic carbon fixation.FMN(flavoprotein) is a iron-sulphur containing complex,present in the mitochondria and aerobic bacteria.The breakdown of this complex releases NADH dehydrogenase enzyme which is responsible for the reduction of NADP+ to NADPH in photosynthetic bacteria through the process of reverse electron transport.