The plant cell is the elementary unit of a living organism - a plant. It contains components that are inherent in all eukaryotic organisms: nucleus, cytoplasm, Golgi apparatus, mitochondria, endoplasmic reticulum, ribosomes and lysosomes, microtubules. However, the plant cell has differences - this is the presence of plastids, vacuoles and a cellulose wall.
Unites all organelles among themselves and participates in the metabolism of a special semi-liquid medium of an elementary living unit (cell) - the cytoplasm. The structure of the cytoplasm is quite complex. It is a multicomponent colloidal solution that can change from a sol to a gel. In this case, the entire cell is permeated with protein filaments that form the cytoskeleton of the structural unit. It consists of water, which accounts for from 60 to 90% of the total mass, proteins (10-20%) and lipids (up to 23%), as well as organic and inorganic substances. The role of the cytoplasm in the life of the cell is very high:
- she is the medium in which chemical reactions take place;
- takes an active part in metabolism;
- supports turgor and thermoregulation;
- performs a supporting function, helps the cell to keep its shape.
Cells influence the semi-liquid medium
and external factors - temperature, light, air composition, amount of water. All this directly affects the movement of the cytoplasm, in which it constantly resides. Due to the movement of a colloidal solution with nutrients (oxygen, ATP, etc.), the elementary unit of a living organism exists. The vital activity of the cell is carried out by a combination of physiological processes. The nutrition of the structural unit of a living organism occurs in the process of biochemical reactions, as a result of which inorganic substances are converted into organic ones. The plant cell breathes oxygen, which is formed during the oxidation of complex substances - carbohydrates, lipids, amino acids. At the same time, during breathing, the synthesis and release of energy necessary to sustain life occurs. The plant cell grows by stretching the cellulose wall and increasing the volume of the cytoplasm and vacuole.
In the aggregate, all these vital processes take part in metabolism, the main essence of which is the formation of new products, their decomposition into smaller components, the removal of decay products from the cell or the deposition in the form of reserve substances. The selection of unnecessary links occurs through the cell wall, and the movement, collection (formation) of new structures is carried out due to the movement of the cytoplasm.
An important property of cells is their ability to multiplyby division. The result of this process is the formation of two daughter structural units of a living organism, which have a set of chromosomes identical to the mother's.
Thus, a plant cell is the smallest living structure of the body, it feeds, breathes, reacts to stimuli, grows, multiplies, and the cytoplasm and organelles immersed in it take part in metabolism.
