Ultrastructure of golgi apparatus : (1) Golgi apparatus was first recognized by Italian Physician Camillo Golgi (1898) in nerve cell of wild owl.
(2) The structure of golgi apparatus appears to be complex. Under the electron microscope, the structure appears as stacks of flattened sacs (cistemae) which are bounded by a membrane having a smooth surface.
(3) These are often connected with flattened sacs or vesicles of various shape and size.
Functions of golgi apparatus :
(1) Secretion: It has been established that the cells that perform secretory functions have well developed golgi apparatus. The secretion may be in the form of lipids, enzymes, hormones, etc.
(2) Cell wall formation in plants : In plants, dictyosomes are known to synthesize pectin and some carbohydrates necessary for the formation of the cell walls.
(3) Mucilage and gums : Mucilage and gums secreted in the plant cells are due to the action of golgi apparatus (indirectly).
(4) Acrosome formation : During spermato¬
genesis, golgi apparatus forms the acrosome.
(5) Lysosome formation : It has been established that secretory vesicles or primary lysosomes are produced from the sacs of the golgi apparatus.
(6) Membrane transformation : Golgi bodies are also involved in the transformation of one type of membrane into another type.
(7) Presence of enzymes: Several enzymes like glycosyl transferase, triaminopryophosphatase have been localised in golgi bodies.
(8) Storage, condensation and packaging of the materials : The golgi bodies are involved in storage, condensation, packaging and transfer of materials. The packaging in a golgi body involves wrapping of a membrane around a particular secretion and discharging it through the plasma membrane