Inhibitors of the electron transport system,such as cyanide (CN^-)and carbon monoxide (CO),inhibit complex IV by binding to the heme iron cofactor.What is the resulting effect on oxidative phosphorylation? A) Electrons pass through the electron transport system, but no protons are pumped. B) Protons are pumped, but no electron transport occurs. C) The electron transport system occurs normally, but no ATP is synthesized. D) Electron transport is disabled, and no protons are pumped.

Question

Quizplus · Accepted Answer

Inhibitors of the electron transport system, such as cyanide and carbon monoxide, bind to the heme iron cofactor of Complex IV and disable electron transport. As a result, no protons are pumped across the inner mitochondrial membrane, which means oxidative phosphorylation cannot occur. The lack of proton gradient prevents ATP synthesis. Therefore, the best choice is D, electron transport is disabled, and no protons are pumped.

Inhibitors of the Electron Transport System,such as Cyanide (CN-)and Carbon

Inhibitors of the Electron Transport System,such as Cyanide (CN^-)and Carbon