Explain ETS?

The electron transport system, or ETS, is found in the inner mitochondrial membrane.

It aids in the release and utilization of energy stored in NADH₂ and FADH₂. An NADH dehydrogenase (complex I) oxidizes NADH₂  produced during glycolysis and the citric acid cycle .

Similarly, FADH₂ (complex II) produced during the citric acid cycle is transferred to ubiquinone.

Ubiquinone electrons are taken up by cytochrome -bc₁ (complex III) and transferred to cytochrome c. Cytochrome c serves as a mobile carrier between complex III and the cytochrome c oxidase complex, which contains cytochrome a and a₃, as well as copper centres (complex IV). Finally, cytochrome-a₃ donates electrons to free molecular oxygen, and oxygen serves as the final electron acceptor at the end of ETS. Oxygen receives two protons from the aqueous medium and forms one water molecule.

The process of transferring electrons from each complex is accompanied by the production of ATP from ADP and inorganic phosphate by the action of ATP synthase (complex V). The amount of ATP produced is determined by the oxidized molecule. The oxidation of one molecule of NADH results in the production of three ATP molecules. On oxidation, one molecule ofFADH₂ yields two ATP molecules.

Therefore, the electron transport system, or ETS, is found in the inner mitochondrial membrane. It aids in the release and utilization of energy stored in NADH₂ and FADH₂.