The structure of the human cell: just about the complex

A person's cell does not differ from a similar onestructure in the body of other animals, if we consider only the general outline of the structure. Analyzing the structure of the human cell, cytologists distinguish two areas that differ in functions - the nucleus and the cytoplasm. Daily activity, ensuring the constant needs of a unit of all living things performs cytoplasm.

All specific functions, such as abbreviationsmuscle cells or the transmission of a nerve signal, are also performed by the cytoplasm. Therefore, cytoplasm differs in different cell types. But the core of the structure is the same even in different species.

The structure of the nucleus of the cell is rather monotonous inunits of living of different types. There are chromatin and nucleolus lumps. Chromatin is not a chemical compound at all, it's just DNA in a "packaged" state. In chromatin, there are also RNA and a few histone proteins.

The core is often round or oval. But there are also oblong, and separated by transverse constrictions (as happens in neutrophils). Considering the structure of the human cell, it should be noted that there is an entire system of membranes and an interphase (outside division) core is always surrounded by a nuclear envelope. In the shell there are holes called nuclear pores. Through them, macromolecules pass into the nucleus and out of it.

The internal environment of the nucleus is very different from the mediumcells, this is provided by thin diaphragms of the pores, which pass only the substances needed by the core inside. So the nucleus exchanges chemical information with the cytoplasm. In the nucleolus, rRNA is formed, which is necessary for the multiplication of the cell. Often the nucleoli merge into one and in the microscope one large nucleolus can be seen.

Nuclear Juice by Chemical Composition - Colloidalsolution of proteins, it is poorly colored on the preparations for the electron microscope and looks like a bright area in microphotographs. This is a fairly sparse environment, where the diffusion of metabolites is facilitated, and the genetic material can move extremely fast.

And what does the cytoplasm do? Its "duties" do not include only the organization of reproduction, everything else it can do. The structure of the human cell is such that the basis of life - oxidation, occurs precisely in the cytoplasm. It consists of many small structures called organelles or organoids, analogous to organs in a large organism.

Most organelles aremembrane structures. Do not contain membranes only free ribosomes, centrioles, cilia and flagella (all three types of organelles are composed of microtubules), as well as fibrillar structures (microfilaments and fibrils).

The structure of the human cell is membrane in principle, thenthere are all sections covered with membranes. Mitochondria, for example, generally have two layers of membranes in which the synthesis of energy molecules - ATP as a result of cellular respiration - occurs. Mitochondria are unique, because they are parasites that have become symbionts. They have their genome and are generally quite independent. It is assumed that they lead the genus from bacteria.

Ribosomes, which sometimes combine inpolyribosomes, are engaged in the synthesis of the protein necessary for the cytoplasm. And it is very necessary not only to build structures, but also to keep the balance of osmotic pressure in the norm.

The endoplasmic reticulum isbubbles connected to each other. Some of them have ribosomes. The protein, which they synthesize, does not float in the cytoplasm juice - the cytosol, but is isolated before excretion from the cell or when used for other needs.

Apparatus Golgi - something like a pile of bags. It accumulates and sorts various substances. Proteins here acquire their final structure, and also here lysosomes are formed.

By the way, about lysosomes. They destroy unnecessary components of cells, if something is wrong with them, then accumulation diseases develop. After the death of the cell, they destroy even the environment of the dead dead unit of the living, and not only itself.

The structure of a living cell differs from the structure of the dead in the first place in that the karyolysis occurs in the deceased - the decay of the nucleus and the digestion of the cell contents after the resorption of the lysosome membranes.