Golgi apparatus: structure and functions of organelles

The Golgi apparatus is an important organelle, which is present in almost every eukaryotic cell. Perhaps the only cells in which this complex is absent are the red blood cells of vertebrates. The functions of this structure are very diverse. It is in the tanks of the device that all the compounds produced by the cell accumulate, after which their further sorting, modification, redistribution and transport takes place.

Despite the fact that the Golgi apparatus was discovered as far back as 1897, and to this day some of its functions are being actively studied. Let's consider more detailed features of its structure and functioning.

Golgi apparatus: structure

This organelle is a collection of membrane tanks that closely adjoin each other, resembling a pile. The structural and functional unit here is diktiosoma.

Diktiosoma is a separate, independent part of the Golgi apparatus, which consists of 3 to 8 closely adjacent tanks. A stack of these membrane tanks is surrounded by a system of small vacuoles and vesicles - this is how the transport of substances takes place, as well as the connection of dictyosomes between themselves and other cellular structures. As a rule, animal cells have only one diktiosome, while in plant structures there can be many.

In the diktiosome, it is common to separate the two ends-the cis and trans sides. The cis-side faces the nucleus and the granular endoplasmic reticulum. Synthetic proteins and other compounds are transported here as membrane vesicles. At this end of the diktiosome, new tanks are constantly being formed.

The trans-side faces the cell membrane. As a rule, it is a bit wider. Connections that have already gone through all the stages of the modification fall into this category. From the lower tank, small vacuoles and vesicles are constantly torn off, which transport substances to the desired organelles of the cell.

Golgi apparatus: functions

As already mentioned, the functions of organelles are very diverse.

• Here the modification of newly synthesized protein molecules is carried out. In most cases, a carbohydrate, sulfate or phosphoric radical is attached to the protein molecule. Thus, the Golgi apparatus is responsible for protein formation of the plasma membrane, enzymes and proteins of lysosomes.
• The Golgi apparatus is responsible for transporting the modified proteins to specific areas of the cell. From the trans side, small bubbles are constantly separated, which contain the ready-made proteins.
• Here, all lysosomal enzymes are formed and transported.
• In the cavities of cisterns there is an accumulation of lipids, and later the formation of lipoproteins - a complex of protein and lipid molecules.
• The Golgi apparatus of a plant cell is responsible for the synthesis of polysaccharides, which then go on to form the cell wall of the plant, as well as mucus, pectins, hemicellulose and waxes.
• After dividing the plant cell, the Golgi complex takes part in the formation of the cell plate.
• In the spermatozoon, this organelle takes part in the formation of acrosome enzymes, with the help of which the egg shells are destroyed during fertilization.
• In the cells of the protozoans, the Golgi complex is responsible for the formation of contractile vacuoles, which regulate the osmotic pressure.

Of course, this is not a complete list of all the functions performed. Modern scientists still conduct a variety of studies using the latest technology. It is likely that in the next few years the list of functions of the Golgi complex will grow significantly. But even today it can be said with certainty that this organelle supports the normal vital activity of both cells and the whole organism as a whole.