<prompt> Which of the following is an ionophore?Carboxin2, 4 dinitrophonalAtractilosideValinomycin  <response>: Valinomycin: It produced by a type of Streptomyces. Transpos K from the cytosol into matrix and H from matrix to cytosol, thereby decreasing the proton gradient.so it is an ionophore.Ref: MN Chatterjea Textbook of Medical Biochemistry, 8th edition, page no: 146 