Inhibitors of Oxidative Phosphorylation The following chemicals inhibit oxidativ
ID: 213161 • Letter: I
Question
Inhibitors of Oxidative Phosphorylation The following chemicals inhibit oxidative phosphorylation Cyanide: Cyanide is a naturally occurring compound that binds to protein complex IV of the mitochondrial electron transport chain and prevents transfer of electrons from the protein Metformin: At the cellular level, chemically synthesized metformin, a drug commonly prescribed for Type 2 diabetes, inhibits mitochondrial respiration by blocking complex I Dinitrophenol: Dinitrophenol is a metabolic poison that can be sold legally as a pesticide Although it is lethal to humans, it is also sold as an unregulated weight-loss product. This molecule can bind to H ions and then, because the molecule is nonpolar, it diffuses across cell membranes. Oligomycin: This is an antibiotic that inhibits ATP synthase by blocking its proton channel. The proton channel is necessary for oxidative phosphorylation of ADP to ATP 3. Explain how each inhibitor will affect the flow of electrons in cellular respiration. 4. Explain how each drug will affect the flow of energy in cellular respirationExplanation / Answer
Cyanide - Hydrogen cyanide binds to hemoglobin instead of O2. Hence the hemoglobin bind cyanide is transported throughout the body and is released in mitochondria where it binds to cytochrome C oxidase thus preventing the electron transport to O2.In this way cyanide prevents oxidative phosphorylation.
Metformin - Metformin is generally thought to be the inhibitor of respiratory complex I (NADH:ubiquinone oxidoreductase) that leads to energetic stress by decreasing ATP synthesis by oxidative phosphorylation.
Dinitrophenol - Dinitrophenol (DNP) is an uncoupler, or has the ability to separate the flow of electrons and the pumping of H+ ions for ATP synthesis. Dinitrophenol disrupts the H+gradient reducing ATP synthesis.
Oligomycin - Oligomycin binds to the proton channel of ATP Synthase, therefore preventing oxidative phosphorylation.