Definition: Biomolecular machinery present in prokaryotic membranes and eukaryotic mitochnodria that couples the flow of electrons to proton pumps in order to convert energy from sugar to ATP.
The electron transport chain couples the transfer of an electron from NADH to molecular oxygen (O2) with the pumping of protons (H+) across a membrane. The charge gradient that results across the membrane serves as a battery to drive ATP Synthase.
