Question

Which of the following statements about the electron transport chain is true? a. The proton gradient established during electron transport is a form of potential energy. b. Protons are pumped out of the mitochondria by the complexes of the electron transport chain. c. The electron transport chain can be found in the mitochondria of aerobic bacteria and other cells. d. ATP synthesis associated with the electron transport chain is an example of substrate level phosphorylation. e. The movement of protons down a concentration gradient is an endergonic process.

Answer 1

Ans.

The electron transport chain is defined a series made up of electron transporters that transfer electrons to their acceptors from donors. The transfer of electrons is coupled with proton transfer across the membranes of mitochondria, as protons are pumped out from mitochondrial matrix to outside or mitochondrial inter-membrane space.

Thus, the correct answer is 'option b). protons are pumped out of the mitochondria by the complexes of the electron transport chain.'