Uncoupler in ETC: (A) H2S, (B) Antimycin a, (C) 2, 4-dinitrophenol, (D) Barbiturates
Answer is C. Dinitrophenol (DNP) a potent uncoupler is amphipathic and increase the permeability of the lipoid inner mitochondrial membrane to protons (H+), thus reducing the electrochemical potential and sho-circuiting the ATP synthase. In this way, oxidation can proceed without phosphorylation.Ref: MN Chatterjea Textbook of Medical Biochemistry, 8th edition, page no: 146