Intermembrane space is the space between outer and inner membrane, of a mitochondria/ chloroplast. It is the site of oxidative phosphorylation process. H+ ions are transported from the cellular matrix to the intermembrane space, and this ultimately leads to generation of a proton graident and generation of energy. An increase in the intermembrane space may lead to decresae in the space of inner membrane and therefore, less space for electron transport chain and ATP synthase, which reside in the inner membrane. This ultimately leads to less energy production.