A prokaryotic cell is, in fact, just a structured organism that retains the features of distant ancestors. They are systematically allocated to a separate kingdom of nodules, which includes bacteria and cyanobacteria (blue-green algae).
What is so "simple" in the structure of pre-nuclear organisms? A prokaryotic cell does not have a nucleus surrounded by its own membrane, mitochondria, and plastids. At the center of the cytoplasm is a nucleoid (nucleotide), which consists of one nucleoprotein structure containing a circular DNA molecule. This complex is called the bacterial chromosome. The cell itself of bacteria and blue-green algae is separated from the external environment by a dense cell wall or mucous capsule and membrane. The wall of an elementary structural unit consists mainly of the substance murein (formed by proteins and carbohydrates), which performs the function of the external skeleton, shaping the cell and protecting it from external stimuli. The inner membrane performs the following functions: protective, transport, perception of irritations and differentiation.
The internal structure of a prokaryotic cell suggests that the cytoplasm and its composition are much poorer than that of a nuclear (eukaryotic) cell. It contains ribosomes, which are necessary for protein synthesis. There are also membrane structures that perform the functions of missing organelles - mitochondria, endoplasmic reticulum,
Golgi apparatus and plastids. For example, a prokaryotic cell has a protrusion of the membrane, which is called the mesosome. It is here that the process of respiration and the release of energy from bacteria occurs.
Also, prenuclear organisms are capable of spore formation, however, they do not reproduce with their help. Spores or cysts are dense membranes that help bacteria survive adverse conditions. To maintain life in unusual conditions, they are able to accumulate nutrients - fats, complex carbohydrates.
A prokaryotic cell can multiply by division, budding, and conjugation. The method of reproduction depends on the type of bacteria or cyanobacteria. Division and budding are methods that allow you to quickly increase the population. Conjugation, which occurs in Escherichia coli, is a sexual process that contributes to an increase in hereditary variability in microorganisms.
Thus, prokaryotes are pre-nuclear cells that do not have a formed cell nucleus and are devoid of many membrane organoids, but are capable of changing. It was they who were able to adapt to life in conditions in which no one else survives - a nuclear reactor, oil wells. A huge number of representatives of the kingdom of nodules are pathogenic and can cause various diseases in people, animals and plants (dysentery, tonsillitis, tuberculosis). Also, some microorganisms live in symbiosis with eukaryotes (symbiogenesis), for example, nitrogen - fixing nodule bacteria that settle on the roots of legumes.