Meaning of Golgi Apparatus

Golgi Apparatus

The notion of apparatus can refer to the grouping of elements that, acting in a coordinated and joint way, carry out the same function. There are multiple devices: among them, the Golgi device.

The organelle found in eukaryotic cells is called the Golgi apparatus and is responsible for completing the process of production of certain proteins. This apparatus is made up of about eighty dictyosomes, which are sets of small sacs known as saccules. The dictyosomes, flattened in shape, are placed one above the other and are protected by a membrane.

Golgi apparatus, also called the Golgi apparatus, Golgi body and golgisoma, was discovered by Santiago Ramon y Cajal in 1897. Later, Camillo Golgi was in charge of accurately describing everything related to this organelle, which ended up adopting the name of the Italian doctor.

The saccules can be grouped in several ways: groups of between four and eight saccules are usually formed, which make up the dictyosomes. Through different tubes, substances can pass from one saccule to another. The external face of the saccules is directed towards the system called the endoplasmic reticulum.

Among the functions carried out by the Golgi apparatus are the production of the acrosome that is part of the sperm and the development of the primary lysosomes; the elaboration of plasma membrane; cell secretion; and the alteration of the substances synthesized by the rough endoplasmic reticulum. In general, the Golgi apparatus can be said to modify and distribute the synthesized macromolecules throughout the cell.

Smooth endoplasmic reticulum vesicles

In the smooth endoplasmic reticulum, vesicles form which, when united, create tube-vesicular aggregates that are brought to the cis region of the Golgi apparatus by means of motor proteins. The latter, on the other hand, can advance thanks to the guidance of some microtubules and, when fused with the membrane of the apparatus, empty their contents into the lumen.

The molecules that enter the Golgi apparatus are modified, tagged, and then shipped to their final destination. Proteins that are carried to distant parts of the apparatus reach the trans region, and enter a complex network of vesicles and membranes. This is where most of them are marked and sent to their respective destinations through one of the following three types of vesicles, depending on their marker:

* exocytosis vesicles: they are those that contain proteins that will be released into the extracellular medium. After the internalization of the proteins, the closure of the gallbladder occurs and it immediately goes to the plasma membrane, with which it unites to release the content, in a process known as constitutive secretion. An example of this can be seen when the antibodies are released by activated B lymphocytes;

* secretion vesicles: these are those that also have the proteins that must be released into the extracellular medium, although it is important to note that, after their formation, these vesicles are stored in the cell and are kept there waiting for the signal that tells them to start their activity. At that time, they move towards the plasma membrane, where they discharge their contents, just as exocytosis vesicles do. The name of this process, which occurs when neurons release neurotransmitters, is regulated secretion;

* Lysosomal vesicles: These vesicles are responsible for transporting proteins to lysosomes, small organelles that contain a large number of acidic hydrolases. Regarding the type of proteins, they can be membrane or digestive enzymes. To transfer its contents to the lysosome, the gallbladder must fuse with a late endosome, as occurs when digestive proteases are sent to lysosomes.

Golgi Apparatus