When the structure is considered, the functions of the cell,much attention is paid to those structures that are involved in the conservation and transfer of genetic data. These complex elements are also involved in regulating the activity of these or other structures.
It should be noted that the value of the nucleus as a placepreservation of hereditary material, as well as its main role in the identification of phenotypic features have been identified quite a long time. One of the first to demonstrate this role was Hammerling (a German biologist).
Functions of the cell nucleus are reduced mainlyto the provision of life. These permanent structures have an ovoid or spherical shape. The length of the first is about 20 μm, and the diameter of the latter is about 10 μm.
The kernel functions are divided into two general groups.The first includes tasks related to the storage of hereditary data. The second group includes the core functions associated with the implementation of this information, with the provision of protein synthesis.
The first group includes the processes providingThe preservation of genetic information, which is represented by an unchanged DNA structure. These functions of the nucleus are due to the presence of "repair enzymes". They eliminate sudden damage in the DNA molecule. Due to this, DNA molecules remain practically unchanged.
The kernel functions are also related to processesreduplication, or playback. As a result, absolutely identical (and quantitatively and qualitatively) volumes of hereditary data are formed. In nuclei, the hereditary material is changed and recombined. This is observed in the process of meiosis. In addition, the nuclei take a direct part in the distribution of DNA molecules during cell division.
The second group includes the processes associated withdirectly with the formation of a protein synthesis apparatus. In eukaryotic nuclei, ribosomal "subunits" are formed. This is due to the combination of ribosomal RNA, synthesized in the nucleolus, and ribosomal proteins synthesized in the cytoplasm.
Thus, the kernels are not onlya repository of hereditary data, but also the place where this information is reproduced and its functioning. In this regard, the violation or loss of any of the functions listed above is disastrous for the cell.
So, for example, violations in the reparation processcan provoke a change in the primary structure of DNA, which automatically leads to a change in protein structures. This, in turn, will certainly affect the specific activity of proteins, which can change so much that it will not be able to provide the basic functions of the cell. This leads to her (cell) death.
Disturbances in the process of DNA reduplicationstop the multiplication of cells or cause the appearance of cells that possess an inferior set of hereditary information, which is also very harmful to the structure as a whole.
To the death of the cell are alsoprocesses of distribution of hereditary material during division. Fallout due to lesions in the nucleus or as a result of a disorder in any regulatory processes of RNA synthesis (of any form) will automatically stop the protein synthesis or lead to serious errors in it.
It should be noted that the term "core" was usedthe first time in 1833 by Browne. So designated globular permanent structures in plant cells. Later this term was also used in the study of higher organisms.
As a rule, there is one nucleus in the cell (there are alsomultinuclear cells), consisting of a membrane that separates it from the cytoplasm, nucleolus, chromatin, karyoplasm (nuclear juice). All these components are found in virtually all non-fading eukaryotic structures.
