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Structure of Golgi Apparatus:

Blausen 0435 GolgiApparatus
  1. Golgi apparatus varies in sized and form in different cell types, but usually has similar organization for any one kind of cells.  The Golgi apparatus appears as a coarse network under a light microscope.
  2. Electron microscope shows it is central stack of parallel, flattened, inter communicating sacs or cisternae and many peripheral tubules and vesicles.
  3. The cisternae vary in number from three to seven in most animal cells and from ten to twenty in plant cells.
  4. Secretary materials reach the Golgi apparatus from the SER through their inter connections, and also by way of transport vesicles which bud off from the SER and fuse with the Golgi cisternae on the forming face.
  5. Tubules form a complicated network towards the periphery and maturing face of the apparatus.
  6. Golgian vacuoles are expanded part of the cisternae which have become modified to form vacuoles.  The vacuoles develop from the concave or maturing face.  Golgian vacuoles contain amorphous or granular substance.  Some of the golgian vacuoles function as a lysosomes. 

Functions of Golgi apparatus:

  1. Golgi apparatus is metabolically very active and many functions have been assigned to it.
  2. The Golgi complex modifies sorts and packages proteins and lipids coming from the ER.
  3. Chemical labels are added to send the products to other specific parts of the cell or out of the cell.
  4. The Golgi apparatus synthesizes some simple carbohydrates such as galactus, sialic acid and certain poly saccharides, pectin compounds from simple sugars.
  5. The Golgi apparatus links carbohydrates with proteins coming from ER to form glycol proteins.  This process is called glycol sylation.
  6. Lipids and proteins coming from the ER or complexed into lipoproteins in the Golgi apparatus.
  7. The production of hormones by endocrine glands is mediated through Golgi apparatus.
  8. In many mammalian tumor and cancer cells the Golgi complex has been described as the site of origin of pigment granules (melanin). 
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