NEET BIOLOGY

Detailed explanation-1: -The ETC is a collection of proteins bound to the inner mitochondrial membrane and organic molecules, which electrons pass through in a series of redox reactions, and release energy. The energy released forms a proton gradient, which is used in chemiosmosis to make a large amount of ATP by the protein ATP-synthase.

Detailed explanation-2: -During the light-dependent reactions, an electron that’s excited in PSII is passed down an electron transport chain to PSI (losing energy along the way). In PSI, the electron is excited again and passed down the second leg of the electron transport chain to a final electron acceptor.

Detailed explanation-3: -In light reaction I, electrons are passed on to iron-sulfur proteins in the lamellar membrane, after which the electrons flow to ferredoxin, a small water-soluble iron-sulfur protein.

Detailed explanation-4: -Nicotinamide adenine dinucleotide phosphate, an energy carrier molecule produced in the light reactions of photosynthesis. NADPH is the reduced form of the ele ctron ac ceptor NADP+. At the end of the light reactions, the energy from sunlight is transferred to NADP+, producing NADPH.

Detailed explanation-5: -In plants and other photosynthetic organisms, an ETC serves to oxidize NADPH (a phosphorylated version of the electron carrier NADH). In both cases, free energy released when the redox reactions of an ETC are coupled to the active transport of protons (H+ ions) across a membrane.