Prokaryotic cell - the cell of the body

A prokaryotic cell is, in fact, a simple arranged organism that retains the features of distant ancestors. They are systematically isolated in a separate kingdom of bloom, which includes bacteria and cyanobacteria (blue-green algae).

What is so "simple" in the structure of the pre-nuclear organisms? A prokaryotic cell does not have a nucleus surrounded by its own membrane, mitochondria and plastids. In the center of the cytoplasm is a nucleoid (nucleotide), which consists of a single nucleoprotein structure containing a circular DNA molecule. This complex is called a bacterial chromosome. The very cell of bacteria and blue-green algae from the external environment is separated by a dense cell wall or mucous capsule and membrane. The wall of the elementary structural unit consists mainly of the murein substance (formed by proteins and carbohydrates), which functions as the outer skeleton, giving the cell shape and protecting it from external stimuli. The internal membrane performs the following functions: protective, transport, perception of irritation and delimiting.

The internal structure of the prokaryotic cell suggests that the cytoplasm and its composition are much poorer than that of the nuclear (eukaryotic) one. It contains ribosomes, which are necessary for protein synthesis. Also there are membrane structures that perform the functions of missing organelles - mitochondria, endoplasmic reticulum, Golgi apparatus and plastids. So, for example, the prokaryotic cell has a protrusion of the membrane, which is called the mesosome. It is here that the process of breathing and releasing energy in bacteria takes place.

Also, pre-nuclear organisms are capable of spore formation, but they do not reproduce with their help. Spores or cysts are dense membranes that help bacteria survive unfavorable conditions. To maintain life in conditions unusual for them are able to accumulate nutrients - fats, complex carbohydrates.

A prokaryotic cell can multiply by fission, budding, and conjugation. The method of reproduction depends on the type of bacteria or cyanobacteria. Division and budding are methods that allow a fairly rapid increase in the population size. Conjugation, which occurs in E. coli, is a sexual process that contributes to an increase in hereditary variability in microorganisms.

Thus, prokaryotes are dendritic cells that do not have a decorated cell nucleus and are devoid of many membrane organelles, but capable of changing. They were able to adapt to life in an environment in which no one else survives - an atomic reactor, oil wells. A huge number of representatives of the kingdom of bloomers are pathogenic and capable of causing various diseases in humans, animals and plants (dysentery, angina, tuberculosis). Also, some microorganisms live in symbiosis with eukaryotes (symbiogenesis), for example, nitrogen - fixing nodule bacteria that settle on the roots of legumes.