The Golgi body is actually a pile or stack of membranous structures called cisternae. The numbers of cisternae in a single stack vary between 6-8.
In some protists, however, the number could extend up to 60. The Golgi bodies are found in both plant & animal cells.
The cisternae of Golgi body have four structural components i.e., cis-Golgi, endo-Golgi, medial-Golgi and trans-Golgi. The vesicles extending from endoplasmic reticulum fuse with the network.
These vesicles then enter the stacks of Golgi body and finally reach the trans-Golgi. The different regions of Golgi apparatus contain different types of enzymes. These enzymes have certain specific tasks assigned to them. Vesicles leave the Golgi apparatus from the side of trans-face. The Golgi apparatus is an important organelle of eukaryotic cells. Directing the carbohydrates and proteins required by the body to their correct destination is the primary job of Golgi body.
- The main function of Golgi apparatus is to carry out the processing of proteins generated in the endoplasmic reticulum. Golgi apparatus also transports protein to the different parts of the cell.
- The Golgi enzymes present in membranous disks of cisternae carry out the modification of cargo proteins. Modification of various substances is carried out by enzymes in cisternae with the help of processes like phosphorylation and glycosylation.
To carry out the glycosylation and phosphorylation processes, nucleotide sugars are imported by the Golgi apparatus from the cytosol.
Polysaccharides are attached with proteins in order to form carbohydrates.
One of the tasks of Golgi apparatus is carrying out the breakdown of proteins and the formation of small, active fragments.
Sulfate groups are added to protein molecules in the Golgi apparatus.
Incorporation of phosphate molecules onto molecules of proteins is also an important task carried out in the Golgi apparatus.
Transportation of lipids around cells and creation of lysosomes are the important functions carried out by Golgi apparatus.
Synthesis of proteoglycans is carried out by the Golgi body. The proteoglycans are found in the extracellular matrix of animal cells.
Carbohydrates are synthesized in the Golgi body. The process of carbohydrate synthesis involves the production of polysaccharides and glycosaminoglycans (GAGs).
The long, un-branched polysaccharides and GAGs are attached to proteins in order to form proteoglycans.
The GAGs are polymerized by enzymes present in Golgi body with the help of xylose link; it leads to the formation of core proteins.
Sulfation is an important task carried out by the Golgi body. The sulfating of substances passing through the lumen of Golgi body is carried out with the help of sulfotransferases.
Golgi apparatus plays an important role in the prevention of destruction of cells (or apoptosis). The Bcl-2 genes present in the Golgi are used for this purpose.