The ribosome is what? Structure of the ribosome

Each cell of any organism has a complex structure, which includes many components.

Briefly about the structure of the cell

It consists of a membrane, cytoplasm, organoids, which are located in them, as well as nuclei (except prokaryotes), in which the DNA molecules are located. In addition, over the membrane there is an additional protective structure. In animal cells it is glycocalyx, in all the others - the cell wall. In plants it consists of cellulose, in fungi - from chitin, in bacteria - from murein. The membrane consists of three layers: two phospholipid and protein between them. There are pores in it, thanks to which the substances are transported inside and out. Near each pore there are special transport proteins, which let only certain substances into the cell. The organoids of an animal cell are:

• Mitochondria, which serve as a kind of "power stations" (in them the process of cellular respiration and the synthesis of energy occurs);
• Lysosomes, which contain special enzymes for metabolism;
• Complex Golgi, intended for the storage and modification of certain substances;
• Endoplasmic reticulum, which is necessary for the transport of chemical compounds;
• Centrosome, consisting of two centrioles, which participate in the fission process;
• Nucleolus, which regulates metabolic processes and creates some organelles;

• The ribosomes, which we will discuss in more detail in this article;
• Plant cells have additional organelles: vacuole, which is necessary for the accumulation of unnecessary substances due to the inability to remove them outward due to a strong cell wall; Plastids, which are subdivided into leucoplasts (responsible for the storage of nutrient chemical compounds); Chromoplasts containing colorful pigments; Chloroplasts, in which there is chlorophyll and where the process of photosynthesis takes place.

The ribosome is what?

Since we are talking about it in this article, it is quite logical to ask such a question. The ribosome is an organoid that can be located on the outside of the walls of the Golgi complex. It should be clarified that the ribosome is an organoid that is contained in a cell in very large quantities. In one there can be up to ten thousand.

Where are these organoids?

So, as already mentioned, the ribosome is a structure that is located on the walls of the Golgi complex. It can also move freely through the cytoplasm. The third option, where the ribosome can be located is the cell membrane. And those organelles that are in this place, practically do not leave it and are stationary.

Ribosome - structure

How does this organelle look like? She looks like a telephone with a tube. The ribosome of eukaryotes and prokaryotes consists of two parts, one of which is larger, the other is smaller. But these two of its components are not joined together when it is in a calm state. This occurs only when the ribosome of the cell directly begins to perform its functions. About the functions, we'll talk later. Ribosome, the structure of which is described in the article, also includes information RNA and transport RNA. These substances are necessary in order to record on them information about the desired cells of proteins. Ribosome, the structure of which we are considering, does not have its own membrane. Its subunits (the so-called two halves of it) are not protected.

What functions does the given organoid perform in the cell?

What the ribosome is responsible for is protein synthesis. It occurs on the basis of information that is written on the so-called matrix RNA (ribonucleic acid). The ribosome, the structure of which we have discussed above, unites its two subunits only at the time of protein synthesis - a process called translation. During this procedure, the synthesized polypeptide chain is located between the two subunits of the ribosome.

Where are they formed?

The ribosome is an organoid, which is created by the nucleolus. This procedure occurs in ten stages, during which the proteins of small and large subunits are gradually formed.

How is the formation of proteins?

Biosynthesis of proteins occurs in several stages. The first of these is the activation of amino acids. In total, there are twenty, combining them with different methods, you can get billions of different proteins. During this stage amino acid-t-RNA is formed from amino acids. This procedure is impossible without the participation of ATP (adenosine triphosphate). Also, magnesium cations are needed for this process. The second stage is the initiation of the polypeptide chain, or the process of combining the two subunits of the ribosome and supplying the necessary amino acids to it. Magnesium ions and GTP (guanosine triphosphate) also participate in this process. The third stage is called elongation. This is directly the synthesis of the polypeptide chain. It occurs by the translation method. Termination - the next stage - is the process of the decomposition of the ribosome into separate subunits and the gradual cessation of the synthesis of the polypeptide chain. Next is the last stage - the fifth is processing. At this stage, complex structures are formed from a simple chain of amino acids, which already represent ready proteins. In this process, specific enzymes participate, as well as cofactors.

Structure of the protein

Since the ribosome, the structure and functions of which we analyzed in this article, is responsible for the synthesis of proteins, let us consider in more detail their structure. It is primary, secondary, tertiary and quaternary. The primary structure of a protein is a specific sequence in which the amino acids that form the given organic compound are located. The secondary structure of the protein is formed from polypeptide chains of alpha-helix and beta-folds. The tertiary structure of the protein provides for a certain combination of alpha helices and beta folds. Quaternary structure is the formation of a single macromolecular formation. That is, combinations of alpha-helices and beta-structures form globules or fibrils. By this principle, we can distinguish two types of proteins - fibrillar and globular. The first include such as actin and myosin, from which the muscles are formed. Examples of the latter include hemoglobin, immunoglobulin, and others. Fibrillar proteins resemble a thread, a fiber. Globulars are more like a tangle of interwoven alpha helices and beta folds.

What is denaturation?

Everyone probably heard this word. Denaturation is the process of destroying the structure of a protein - first a quaternary, then a tertiary, and then - a secondary one. In some cases, the primary structure of the protein is eliminated. This process can occur due to exposure to a given organic matter of high temperature. Thus, denaturation of the protein can be observed when cooking chicken eggs. In most cases, this process is irreversible. So, at a temperature above forty-two degrees, denaturation of hemoglobin begins, so strong hyperthermia is dangerous for life. Denaturation of proteins to individual nucleic acids can be observed in the process of digestion, when by means of enzymes the organism splits complex organic compounds into simpler ones.

Conclusion

The role of ribosomes is very difficult to overestimate. They are the basis of the existence of the cell. Thanks to these organelles, she can create proteins that she needs for a wide variety of functions. Organic compounds formed by ribosomes can play a protective role, transport, the role of catalyst, building material for cells, enzymatic, regulatory (many hormones have a protein structure). Therefore, we can conclude that the ribosomes perform one of the most important functions in the cell. Therefore, there are so many of them - the cell always needs products synthesized by these organoids.