In: Biology
On the basis of the mitochondrial electron transport and ATP synthase inhibitors (myxothaizol, FCCP, Venturicidin, and Ventruicidin + FCCP) list the effects of these on the rates (decrease activity, increase activity, no activity) of oxygen consumption and ATP synthesis in a mitochondrial suspension containing all of the metabolites needed to reduce oxygen and synthesize ATP. Explain your reasoning in each case.
1. Myxothaizol:- myxothaizol inhibits or blocks electron transport at the level of complex 3.so it will reduce the rate of electron flow and DECREASES ATP production.
2. FCCP- it is soluble in lipid bilayer both in protonated neutral form and in their anionic state. In anionic state ,It will pick up protons in inter membrane space and diffuse readily across mitochondrial membrane. When it enters matrix, it can release a proton in it's protonated form. This will dissipate proton gradient and inhibit ATP synthesis.since it is an uncoupling agent that uncouple oxidation from phosphorylation,it will not have effect on 02 Reduction.
3. Valinomycin- valinomycin is an ionophore which uncouple electron transtransfer from oxidative phosphorylation by disdissipating electrochemical gradient. Valinomycin makes inner mitochondrial membramembrane permeable for K+. so that movement of K+ along concentration gradient from cytosol to matrix. Thus decreases membrane potential and ATP synthesis.
4.valinomycin+ FCCP- combination of uncoupling agent FCCP and ionophore valinomycin REDUCES ATP production based on above described mechanism