“…This binding is therefore not only a property of the hexoki nase isoenzymes (which are present, albeit in different proportions, both in fetal and adult rat liver) but depends also on some specific property of the mitochondrial membranes, which changes during development. Very little is known about membrane-associated changes in mitochondria of rat liver during develop ment, except for the studies of Luit et al (16) and Poliak (17,18). However, these studies predominantly concern the inner mitochondrial membrane and to not as yet permit definite conclusions.…”