The intermembrane space is chemically similar to cytosol, but includes a large amount of small proteins as well. As electrons move down the proteins in the electron transport chain, the electrons lose energy to bring H+ ions from the mitochondrial matrix into the intermembrane space. As a concentration gradient of hydrogen ions forms, a protein called ATP synthase harnesses the potential energy of these ions and starts chemiosmosis, where the H+ ions reenter the matrix via this enzyme bound to the cristae (folds of the inner membrane). ADP and a phosphate group are combined to form ATP.
where do h+ ions accumulate in the mitochondria
The intermembrane space the intermembrane space