Human-free cells

Everyone knows that a person is a eukaryote. This means that all its cells have an organelle, in which all the genetic information is contained, is the nucleus. However, there are exceptions. Is there a nuclear-free cell in the human body and what is their significance for life?

Human-free cells

They can not be compared with prokaryotes that have a typical structure. What kind of a non-nuclear cell? There are no nuclei in the blood cells - red blood cells. Instead of this organelle they contain a complex chemical complex of substances, allowing them to perform the most important functions for the body. Blood platelets - platelets and lymphocytes - also non-nuclear cells. There are no nuclei in cells, which are called stem cells. All these structures combine another feature. Since they lack a nucleus, they are not capable of reproduction. This means that the nuclear-free cells, the examples of which were given, die after the performance of their function, and new ones are formed in specialized bodies.

Erythrocytes

They determine the color of our blood. Nuclear-free blood cells, erythrocytes have an unusual shape - a biconcave disk, which significantly increases their surface at relatively small sizes. But the number of them is simply amazing: in 1 square. Mm of their blood is up to 5 million! On average, the erythrocyte lives up to four months, after which it dies and is neutralized in the spleen and liver. New cells are formed every second in the red bone marrow.

Functions of red blood cells

What, instead of the core, contain these non-nuclear cells? These substances are called heme and globin. The first is iron-containing. It not only stains blood in red, but also forms unstable connections with oxygen and carbon dioxide. Globin is a substance of protein nature. A heme containing a charged ion of iron is immersed in its large molecule. By the mechanism of action, these cells can be compared with a fixed-route taxi. In the lungs they attach oxygen. With the current of blood, it spreads to all cells and is released there. With the participation of oxygen, the process of oxidation of organic substances takes place with the release of a certain amount of energy that a person uses to carry out vital activity. The vacant place is immediately occupied by carbon dioxide, which moves in the opposite direction - into the lungs, where it exhales. This process is a necessary condition of life. If oxygen does not reach the cells, then they gradually die off. This can be dangerous for the life of the body as a whole.

Erythrocytes perform another important function. On their membranes there is a protein marker called the Rh factor. This indicator, like the blood group, is very important during blood transfusion, during pregnancy, donation and surgical operations. It must be installed, because with incompatibility, a so-called Rh-conflict can occur. It is a protective reaction, but can lead to rejection of the fetus or organs.

Irrational diet, bad habits, polluted air can cause destruction of red blood cells. As a result, a serious illness occurs, which is called anemia, or anemia. Thus the person feels a giddiness, delicacy, a dyspnea or short wind, a noise in ears. Oxygen deficiency affects the physical and mental activity of a person. It is especially dangerous during pregnancy. If the umbilical cord does not receive enough oxygen to the fetus, this can lead to serious disturbances in its development.

Structure of platelets

Nuclear-free cells are also called platelets. In the inactive state, they really have a flat shape resembling a lens. But when the vessels are damaged, they swell, round off, form unstable outgrowths of the outer layer - pseudopodia. Platelets are formed in the red bone marrow and do not last long - up to 10 days, being rendered harmless in the spleen.

Thrombus formation process

The matrix of the blood platelets contains an enzyme called thromboplastin. When the integrity of the vessels is violated, it appears in the plasma. Under its action, the protein of the blood protrombin passes into its active form, in turn, acting on fibrinogen. As a result, this substance becomes insoluble. It turns into a protein fibrin. Its threads closely intertwine and form a thrombus. The protective coagulation reaction prevents blood loss. However, the formation of a blood clot inside the vessel is very dangerous. This can lead to its rupture and even the death of the body. Violation of the process of coagulation is called hemophilia. This hereditary disease is characterized by an insufficient number of platelets and leads to unnecessary blood loss.

Stem cells

These non-nuclear cells are called stem-in-law. They really are the basis for all others. They are also called "genetically pure". Stem cells are found in all tissues and organs, but most of all they contain bone marrow. They help restore integrity where necessary. Stem cells turn into any other types of cells when they are destroyed. It would seem that in the presence of such a magic mechanism a person must live forever. Why does not this happen? The thing is that with the age of the intensity of differentiation of stem cells is significantly reduced. They are already unable to restore the destroyed tissue. But there is one more danger. There is a high probability of transformation of stem cells into cancer cells, which inevitably leads to the death of any living organism.

Nuclear-free cells: examples and features

In nature, nuclear-free cells are found quite often. For example, blue-green algae and bacteria are prokaryotic. But, unlike human nuclear-free cells, they do not perish after fulfilling their biological role. The fact is that prokaryotes have genetic material. Therefore, they are capable of division, which occurs by mitosis. As a result, two genetic copies of the maternal cell are formed. The hereditary information of prokaryotes is represented by a circular DNA molecule, which doubles before division. This analogue of the nucleus is also called the nucleoid. The plants are nuclear-free living cells of the conducting tissue - sieve tubes.

So, human nuclear-free cells are incapable of dividing, so they exist for a short period of time before performing their function. After this, they are destroyed and intracellular digestion. These include uniform elements (erythrocytes), blood platelets (platelets), and stem cells.