Question

Explain how energy, which is generated by the electron transport chain, is coupled to the formation of ATP by oxidative phosphorylation.

Answer 1

The Electron transport chain plays an important role in the synthesis of ATP.The hydrogen carriers NADH and FADH2 which are synthesized during aerobic respiration help in the production of ATP.These hydrogen carriers are oxidized and to high energy protons and electrons.The electrons are then transported to ETC.They are transported through carrier proteins(Complex I to Complex V).As these electrons move along the chain they lose energy which help in the pumping of protons to the intermembrane space from the matrix, thereby establishing a proton gradient.These electrochemical gradient is responsible for the generation of ATP with the help of ATP synthase (Complex V).This complex consists of two major components F1 and F0 .The F1 head piece is a peripheral membrane protein complex and contains the site for the synthesis of ATP from ADP and inorganic phosphate.F0 is an integral membrane protein complex that forms the channel through which the protons cross the inner membrane.The passage of protons through the channel is coupled to the catalytic site of the F1 component for the production of ATP.For each ATP produced,3H+ passes through F0 from the intermembrane space to the matrix down the electrochemical proton gradient.