What is the Golgi apparatus? Definition:
Of the Golgi apparat is a cell organelle in the immediate vicinity of the nucleus and responsible for the adaptation of proteins. The unfinished polypeptide chains from the ribosomes reach the Golgi apparatus. By adding more proteins, the polypeptide chains are completed, then packed in transport vesicles and transferred to their destination.
The Golgi apparatus owes its name to its discoverer, the Italian physician Camillo Golgi. Thus, the Golgi apparatus is the only organelle named after its discoverer.
The Golgi apparatus forms in the interior of the cell a cave-like compartment, which is enclosed by a membrane. In this own reaction space the modification of the proteins takes place. Furthermore, the digestive vesicles (lysosomes) are also formed in the Golgi apparatus.
Construction of the Golgi apparatus
The Golgi apparatus consists of cisterns, ie several stacked cavities. The slightly curved, flat rooms are surrounded by a membrane and lie in about 5 to 20 layers above each other. Because of this stacked arrangement of the reaction chambers, significantly more proteins can be processed in a small space. With only a single reaction space, the Golgi apparatus would be many times slower in its operation.
The individual cisterns are called Dictyosomes. Often the term is also used as a synonym for the Golgi apparatus.
The dictyosomes are connected via channels. At the edge of the cisterns are the vesicles. As soon as the Golgi apparatus in its cavity completes a corresponding protein, it is transported to the marginal area and cut off into a vesicle and released into the cell interior. The cells have to rely on the Golgi apparatus, since most of the proteins can not be transported without "packaging" through the cytoplasm. It would otherwise react with the cytosol or other organelles.
Function of the Golgi apparatus
The tasks of the Golgi apparatus are to expel vesicles and to transport various substances in the cell. These include water-soluble proteins or metabolic end products. As already mentioned, these substances can not be transported through the cell without vesicles.
The vesicles perform a special task within these processes: transfer of various substances, e.g. Waste materials, in extracellular space (exocytosis).
Furthermore, the Golgi apparatus is involved in the production of glycoproteins and modification of lipid building blocks. Again, proteins must be transported to different (both intracellular and extracellular) locations. The vesicles produced by the Golgi apparatus act as mediators again.