The antibiotic valinomycin (see Section 10.4) is an ionophore that forms a specific complex with potassium ion. Because the complex is lipophilic and can diffuse into the membrane, valinomycin brings about the transport of K⁺ through the inner membrane. Valinomycin acts by decreasing the ∆ψ (membrane potential) component of the pmf, without a direct effect on the pH gradient. Another antibiotic, nigericin, acts as a K⁺/H⁺ antiporter; it carries H⁺ in one direction, coupled with the reverse transport of K⁺. Thus, nigericin dissipates the pH component of the pmf, with little effect on ∆ψ. Which antibiotic, nigericin or valinomycin, do you predict would have the greater effect on oxidative phosphorylation when administered to respiring mitochondria? Assume the antibiotics are added to a suspension of mitochondria in equimolar amounts. Briefly explain your reasoning.