Freshly synthesised by the golgi-apparatus the primary lysosomes are dark and homogenous. When swallowing further substances they transform into secondary lysosomes. When digestion is finished they become residual bodies, telolysosomes or tertiary lysosomes. Abbau von zellfremden Material. Primary lysosmes are roughly spherical and do not contain obvious particulate or membrane debris, i.e. after contact to other material they become secondary or heterolysosomes.
Primary lysosomes are present in all cells, their number is high in micro- and macrophages.