mitochondrion
High-energy electrons are released from NADH and FADH 2 , and they move along electron transport chains, like those used in photosynthesis. The electron transport chains are on the inner membrane of the mitochondrion. As the high-energy electrons are transported along the chains, some of their energy is captured. This energy is used to pump hydrogen ions from NADH and FADH 2 across the inner membrane, from the matrix into the intermembrane space. Electron transport in a mitochondrion is shown in Figure below .