Electron transport chain is located in-

Ans. is 'a' i.e., Inner mitochondrial membrane o As molecules, such as glucose and fatty acids, are metabolized (oxidized) they produce electons (reducing equivalents), which are donated to coenzymes like NAD' and FAD to reduce them into NADH and FADH2.o These reduced forms of coenzymes (NADH, FADH2) need to be oxidized.o This is achei ved when reduced coenzymes transfer their reducing equivalent (electrons) to electron transport chain (ETC) and these reducing equivalents are transported within in the ETC, through a specialized set of electron carriers, to oxygen, i.e.. oxygen is the terminal electron acceptor.o Oxidation of reducing equivalents in the respiratory chain is coupled with phosphorylation of ADPto ATP Q,o This is the most important mechanism for capturing the energy present in various nutrients. As the respiratory chain is located in the mitochondria, the mitochondria have been described as the power house of the cells Q,o Electron transport chain is present in the inner mitochondria] membrane Qo The enzymes of ETC are embedded in the inner membrane.o NADH and FADH2 serv e as substrates for ETC by donating their reducing equivalents (electrons) (PGMECET 07) Components of respiratory chain are: - (i) Flavin mononucleotide , (PGMECET 07) (FMN); (ii) Ubiquinone or Coenzyme Q; (iii) Iron-sulfur (Fe - S) protein associated with FMN and cytochrome b; and (iv) Cytochromes (haeme proteins): Cytochrome b, c1, c, a and a3