Mitotic cycle: features of this process

Division is an important property of cells. Without this process, one can not imagine an increase in the number of different microorganisms or unicellular creatures. In addition, it provides restoration of tissues and even whole organs of multicellular organisms.

It is worth noting that the aggregate of processes that take place between two divisions is called the cell cycle. It passes in stages. Thus, the interphase and the actual mitotic cycle are characterized, in which the cell is divided.

In order to maintain the appropriate amount of genetic material, DNA molecules are doubled . In addition, in the interphase there is a biosynthesis of proteins, as well as the formation of important cell structures.

I must say that the interphase is longer than the division itself. It consists of the following stages:

• Presynthetic period - characterized by active growth processes, the synthesis of proteins and nucleic acids, and the formation of specific activators of the synthetic period. The cell reaches its normal size and restores the organelles necessary for functioning. The duration of this period is several hours or days.

• Synthetic period - characterized by DNA replication and histone synthesis, which are responsible for nucleosomal packing of newly synthesized nucleic acids, as well as for doubling chromosomes and centrioles. The duration of this period is up to 12 hours.

• Post-synthesizing period - lasts until mitosis, characterized by energy accumulation and synthesis of tubulin protein , which is necessary for cell division. This period ends in 2-4 hours.

After the interphase, the mitosis stage passes, which is also characterized by certain successive processes, during which daughter cells are formed with a clearly defined set of chromosomes.

It is worth noting that until today the reasons for the termination of the process of division remain unknown. The mechanism that provokes its renewal is unknown, although hormones are established, in which the mitotic cycle is activated. Factors that control the size of the population of cells are also not fully understood.

The mitotic cycle of cells is influenced by glucocorticoids. Prolactin, thyrotropin, estrogens and androgens are also able to influence cell division in target tissues in a certain way.

It is worth noting the following feature of benign tumors - their cells are characterized by a circadian mitotic cycle (diurnal). It is suggested that with the progression of the tumor, the sensitivity of the organism to the so-called. Caylones - inhibitor cells.

The division and size of the cell population is also affected by the activity of the lysosomal apparatus, since its enzymes are capable of exhibiting a destructive effect.

It should be noted that the process of formation of new cells depends on the type of tissues, the influence of external factors and the physiological state of the organism, therefore, in some cases it may have certain individual characteristics, characterized by further growth of the cell population or termination of this process.