Golgi Apparatus

The Golgi apparatus is a eukaryotic cellular organelle

Structure of the Golgi apparatus

The Golgi apparatus is formed from a pile of small sacs (rather like a pile of plates). This pile is called the dictyosome, and is single in animal cells but multiple in plant cells. The cis face of the Golgi apparatus which is found before the endoplasmic reticulum is distinguished from the trans face which is turned towards the cytoplasm.

Role of the Golgi apparatus

The main role of the Golgi apparatus is to act as a site of transport and as a reservoir for proteins and lipids produced in the endoplasmic reticulum. The apparatus is part of the internal membrane which eukaryotic cells have produced so that macromolecules can be transported.

In particular, they enable post translational changes to be made to the newly produced proteins:

• glycosylation, or addition of sugar onto certain amino acids;
• cleavage of polypeptide precursors (division of peptides bonds)
• sulphation or addition of sulphate to certain amino acids;
• phosphorylation, or addition of phosphate.

These changes make the proteins functional.