Which of the following is an inophor -

Ans. is 'd' i.e., Valinomycin Ionophors Ionophors are ion carrier molecules. These are lipid soluble (lipophilic) compounds that increase the permeability of lipid bilayers to ceain ions. These are two types of ionophors.Mobile ion carriers : - These molecules are capable by binding and carrying specific cations (other than Fr) through mitochondrial membrane. Oxidative phosphorylation can be prevented by ceain ionophors, e.g., Valinomycin. They differ from uncouplers in that they promote the transpo of cations other than H- through the membrane and abolish the membrane potential and proton gradient (pH gradient) across the membrane and phosphorylation is therefore completely inhibited, i.e., ATP synthesis is inhibited.Acetaldehyde dehydrogenase dehydrogenase " v:shapes="_x0000_s1028">Channel formers : - These ionophors form the channels allowing ions to pass through, e.g., gramicidine, nigricine.