Have you heard of cellular intelligence? This rather bold scientific hypothesis states that the organization of the elementary unit of life - the cell - is subject to intelligent logical programs. They are similar to the control of the human body by the most complex organ - the brain. All cell organelles not only have a filigree, logically explicable structure, but are also capable of performing unique tasks. They provide all the vital processes of the cellular biosystem: its nutrition, growth, division, etc. In our article, we will consider such cell organelles as ribosomes. Their functions are in the synthesis of the main organic compounds of the cell - proteins.
Small, but daring
This folk saying is the best suited to the cellular organelle - the ribosome. Discovered in 1953, it is considered the smallest cellular structure, and in addition does not have membranes. That ribosomes are so important can be proved by the following simple fact. All cells without exception: animals, plants, fungi, and even non-nuclearorganisms - contain a huge number of ribosomes. The synthesis of proteins carried out by them provides the cell with proteins that perform building, protective, catalytic, signaling and many other functions in it.
The size of one organelle does not exceed 20 nm, its diameter is about 15 nm, and its shape resembles a spherical toy - a nesting doll. Each subunit is formed within the cell nucleus containing the nucleolus. This is the site of synthesis of ribosome particles. Let us dwell on the structure of the protein-synthesizing apparatus of the cell in more detail.
What's inside
Ribosome consists of two subunits, called large and small. Each of them contains specific proteins associated with ribonucleic acid molecules. The subunits of the organoid, like two puzzles, merge at the moment of protein synthesis, and after its completion they are separated, remaining separately in the cytoplasm of the cell.
As mentioned earlier, RNA is part of the ribosome. The large subunit of the organelle has three nucleic acid molecules connected to 35 peptide molecules, one RNA molecule of the small particle is associated with 20 protein components. Earlier we mentioned the fact that the number of ribosomes is large. It is directly proportional to the intensity of protein biosynthesis processes occurring in the cell. So, in humans and most vertebrates, the largest accumulation of organelles is observed in the cells of the red bone marrow and hepatocytes - the structural units of the liver.
Ribosome proteins
Organelle proteins are heterogeneous in their own wayamino acid composition, therefore, each protein molecule strictly binds only to a certain section of the ribosomal ribonucleic acid. The RNA molecule formed in the nucleolus is connected to the proteids in the tertiary configuration by numerous covalent bonds. Here, in the nucleolus of the cell nucleus, the formation of subunits of the organoid occurs. Thus, the composition of ribosomes includes two types of polymers, namely proteins and ribonucleic acid. In preparation for biosynthesis, ribosomes combine with one molecule of informational ribonucleic acid, which leads to the formation of a complex structure - polysomes.
The number of organelles sitting on the RNA chain will correspond to the number of protein molecules with the same amino acid composition.
Broadcast
Synthetic processes leading to the formation of the final product - protein - are included in the group of assimilation reactions and are called translation. What is the role of ribosomes in it? The beginning of biosynthesis is characterized by the fact that initiation is carried out - the connection of informational ribonucleic acid with a small subunit of the organoid. In the cell cytoplasm, a ribosome is attached to one of the terminal sections, which is a signal for the process of biosynthesis. The next stage, elongation, consists in the interaction of the ribosome with the first two RNA particles, called transport ones. They, like a cargo taxi, deliver amino acids to the organelle, which then moves along the polynucleotide chain.
At the same time, amino acids are linked to each other with the help of peptide bonds, leading to an increase in the protein molecule. The final stage, termination, consists in the fact that in the course of the organelle's movement along the mRNA, it encounters a stop codon, for example, UAA, UGA or UAG. In the area of these triplets, there is a break in the covalent bonds between the protein and the last t-RNA. This results in the release of the peptide from the polysome. Thus, the ribosome is the leading component of the cell, providing the synthesis of its proteins.
In our article, we found out which organic polymers make up ribosomes, and also determined their role in the life of the cell.
