The antibiotic valinomycin 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; itcarries H+ in one direction, coupled with the reverse transport of K+. Thus,nigericin dissipates the pH component of the pmf, with little effect on ∆c.Which antibiotic, nigericin or valinomycin, do you predict would have thegreater 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.

The antibiotic valinomycin 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; itcarries H+ in one direction, coupled with the reverse transport of K+. Thus,nigericin dissipates the pH component of the pmf, with little effect on ∆c.Which antibiotic, nigericin or valinomycin, do you predict would have thegreater 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.

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter3: The Plasma Membrane And Membrane Potential

Section: Chapter Questions

Problem 2TAHL: Assume that a membrane permeable to Na+ but not to Cl- separates two solutions. The concentration of...

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