Golgi Apparatus

Within each cell, both plant and animal, there are essential parts that have a variety of functions. One of these organelles is the Golgi apparatus which is important for dealing with proteins. It is often termed the post office of the cell because it is involved with sending proteins to the places they need to go. It was first discovered in 1898 by Camillo Golgi, an Italian microscopist. He found what would later become known as the Golgi apparatus within nerve cells.

The appearance of the Golgi apparatus varies within different species but it is always made up of flattened membranous sacs which are called cisternae and has small membrane enclosed vesicles. The Golgi apparatus has several important roles including receiving proteins from the endoplasmic reticulum and modifying them. The Golgi apparatus also concentrates, packages, and sorts through proteins before that are sent to the destinations either within the cell or outside of it. The last function of the Golgi apparatus takes place within plant cells and is the area where some polysaccharides are synthesized for use in the plant cell wall.

In the cells of plants, fungi, invertebrate animals and fungi the cisternae are individual units that are spread throughout the cytoplasm. In the cells of vertebrate animals however the cisternae are usually concentrated into one larger more complex Golgi apparatus.

There are three distinct parts of the Golgi apparatus that each functions differently: the bottom, the middle, and the top. The bottom cisternae is the cis region of the Golgi apparatus is the closed area to the cell nucleus. The top of the Golgi apparatus is known as the trans region and is closest to the surface of the cell. The cisternae that are located in the middle are called the medial region of the complex. Each different area of the Golgi apparatus contains different enzymes and performs different functions.

The Golgi apparatus receives proteins from the endoplasmic reticulum and packages them and then sends them on. While the proteins are in the Golgi apparatus they are modify them so that they will only reach the proper destination. This is done by tagging the proteins. Proteins are sent to the Golgi apparatus within a vesicle. When they reach the Golgi apparatus they vesicle fuses with the membrane and then the proteins enter the Golgi apparatus. The Golgi apparatus is essential in the transports of lipids around the cell and in the creation of lysosomes.