Golgi apparatus

• Densely stained reticular structures near the nucleus.
• First observed by Camillo Golgi (1898).
• They consist of flat, disc-shaped sacs (cisternae) of 0.5μm 1.0 μm diameter.
• These are stacked parallel to each other.
• Cisternae are concentrically arranged with convex cis (forming) face and concave trans (maturing) face. Cis & trans faces are totally different, but interconnected.

Function of Golgi apparatus:

• Packaging materials, to be delivered either to the intra-cellular targets or secreted outside the cell.
• Materials to be packaged in the form of vesicles from the ER fuse with the cis face and move towards the maturing face. This is why the Golgi apparatus remains in close association with the endoplasmic reticulum.
• Proteins synthesized by ribosomes on the ER are modified in the cisternae of the Golgi apparatus before they are released from its trans face.
• Golgi apparatus is the important site of formation of glycoproteins and glycolipids.