Question

How does antimycin affect the electron transport chain?

Answer 1

Hint: We know that electron transport is a sequence of redox reactions that mimic a relay race or bucket brigade in which electrons are easily transported from one part to the end point of the chain where the electrons decrease molecular oxygen and produce water.

Complete answer:
As we know, the electron transportation chain is the last aerobic respiration portion and is the only part of the glucose metabolism that uses atmospheric oxygen. Oxygen continually passes through plants; it enters the body via the respiratory system of animals. The electron transport chain is present in multiple copies in the eukaryote inner mitochondrial membrane and in the prokaryotic plasma membrane.
ATP synthesis can occur in vivo if the proton motive force is created artificially without electron transfer, that is without the need for oxidation of the substrate. It is important to note that ATP synthesis is a coupled reaction that is the oxidation of the substrate and phosphorylation reaction are coupled together, neither reaction can occur without the other because the energy of substrate oxidation drives ATP synthesis, inhibitors of the electron transfer will block ATP synthesis, the examples of such inhibitors include cyanide, carbon monoxide and, antimycin A. Antimycin blocks the electron transfer in complex III and inhibits the electron transport chain.

Note:
Remember that the prokaryotic electron transport chain may not require oxygen as some live-in anaerobic conditions. All electron transport chains are commonly characterized by the presence of a proton pump to create a proton gradient across a membrane.