Question

Oxidative phosphorylation is
A. Addition of phosphate group in ATP
B. Formation of ATP by energy released from electrons removed during substrate oxidation
C. Formation of ATP by transfer of phosphate group from a substrate to ADP
D. Oxidation of phosphate group in ATP

Answer 1

Hint: Oxidative phosphorylation is the synthesis of ATP by ADP and Pi.

Complete Answer:
(i) Oxidative phosphorylation: It refers to the synthesis of ATP by ADP and Pi driven by energy released from the oxidation of reducing powers NADH and FADH by transfer of their electrons through electron transport chain to oxygen.
(ii) ETS (electron transport chain) is present in the inner mitochondrial membrane and passes the electrons down a series of carrier i.e. electron carriers and pump protons to the intermembrane space.
(iii) Oxygen acts as the final hydrogen acceptor.
(iv) and proton gradient serves as energy sources for the enzyme ATP synthase to synthesize. ATP.
(v) Unlike phosphorylation where light energy is utilized for the production of proton gradients required for phosphorylation. In respiration it is the energy of oxidation-reduction utilized for the same process. Hence, it is called oxidative phosphorylation.

Hence, the correct option is (B).

Note: (i) In eukaryotic cells, the vast majority of ATP synthesis occurs in the mitochondria by oxidative phosphorylation.
(ii) Oxidative phosphorylation is linked to a process known as electron transport system.