<Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2017) (Learn how and when to remove this template message) </Td> </Tr> <P> The intermembrane space of a Mitochondrion refers to the compartment formed between the inner and outer mitochondrial membranes . </P> <P> 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 . </P>

Where do h+ ions accumulate in the mitochondria