in discussing the possible significance of this observation , it is suggested that if this site were directed so that cation was actively pumped from golgi cisternae into cytoplasm ( and if there were differential water and ion permeabilities in various parts of the endoplasmic reticulum-golgi system ) , then such a pumping mechanism could provide an explanation for the concentrating function of the golgi apparatus .
C0007447
cation
C0022023
ion