The structure of the eukaryotic cell

All living organisms, depending on the presence of the nucleus, can be divided into two broad categories: prokaryotes and eukaryotes. Both these terms are derived from the Greek "karion" - the core.

Those organisms that do not have a nucleus are called prokaryotes - pre-nuclear organisms with nuclear matter in the form of inclusions. The structure of the eukaryotic cell is somewhat different. Unlike prokaryotes, eukaryotes have a formed nucleus - this is their main difference. Prokaryotes include bacteria, cyanobacteria, rickettsia and other organisms. To eukaryotes can be attributed representatives of the kingdoms of Mushrooms, Plants and Animals.

The structure of the eukaryotic cell of various nuclear organisms is similar. The main components are the nucleus and cytoplasm, which together constitute the protoplast. The cytoplasm is a semi-liquid basic substance, or, as it is also called, the hyaloplasm, in which there are cellular structures - organelles, performing various functions. On the outside, the cytoplasm is surrounded by a plasma membrane. Plant and fungal cells have in addition to the plasma membrane a rigid cell membrane. The cytoplasm of plant cells and fungi contains vacuoles - vesicles, which are filled with water with various substances dissolved in it. In addition, the cell contains inclusions in the form of reserve nutrients or final products of metabolism. Features of the structure of the eukaryotic cell are due to the functions of the inclusions in the cell.

Structure and functions of the eukaryotic cell :

• The plasma membrane is a double lipid layer with proteins immersed in it. The main function of the plasma membrane is the metabolism between the cell itself and the environment. Due to the plasma membrane, there is also contact between two neighboring cells.
• Core - this cell element has a two-membrane shell. The main function of the nucleus is the preservation of hereditary information - deoxyribonucleic acid. Thanks to the nucleus, cellular activity is regulated, the genetic material is transmitted to the daughter cells.
• Mitochondria - these organelles are present only in plant and animal cells. Mitochondria, like the nucleus, have two membranes, between which there are internal folds - cristae. The mitochondria contain ring DNA, ribosomes, many enzymes. Due to these organelles the oxygen stage of cell respiration is carried out (adenosine triphosphoric acid is synthesized).
• Plastids - are present only in the plant cell, since their main function is the realization of photosynthesis.
• Endoplasmic reticulum (reticulum) is a whole system of flattened sacs - cisterns, cavities and tubules. On the endoplasmic reticulum (rough) are located important organelles - ribosomes. In the network cisterns, proteins are ripened and ripened, which are also transported by the network itself. On the membranes of the smooth reticulum, the synthesis of steroids and lipids is carried out.
• The Golgi complex is a system of flat single-membrane cisterns and bubbles attached to the extended ends of tanks. The function of the Golgi complex is the accumulation and transformation of proteins and lipids. Here, secretory vesicles are formed, which carry substances out of the cell. The structure of the eukaryotic cell is such that the cell has its own mechanism for isolating waste substances.
• Lysosomes - single-membrane vesicles that contain hydrolytic enzymes. Thanks to lysosomes, the cell digests damaged organelles, dead cells of organs.
• Ribosomes - there are two types, but their main function is the assembly of protein molecules.
• Centrioles is a system of microtubules that are built from protein molecules. Thanks to centrioles, the inner skeleton of the cell is formed, it can maintain its constant shape.

The structure of a eukaryotic cell is more complex than prokaryote cells. Due to the presence of the nucleus, eukaryotes have the ability to transmit genetic information, thereby ensuring the constancy of their species.