Bacteria may seem simple organisms, but do not be fooled by this simplicity.In fact, the structure of the bacterial cell makes it very adapted to their life needs.Some bacterial cells are unique education and explain their unusual biological properties.
Previously, the word "bacteria" means "any prokaryotes."Nowadays allocate more primitive and small forms of life - Archaea.They differ from true bacteria.The latter has properties for archaea uncharacteristic.
Before the discovery of electron microscopes in the 50 years of the previous century, the structure of the bacterial cell was a mystery to scientists.Specifically, the bacteria were understood simply as "a little bit of protein and lipids."The structure of the bacterial cell was the object of study only after opened the mysterious world of the smallest forms of life.
allocate at least 4 kinds of bacteria in shape: spherical cocci, filamentous bacterium, bacillus coli, and twisted rods spirillum.The small size of the bacterial cell gives it an evolutionary advantage, because the ratio of surface area / volume becomes quite large, which allows the bacterial cell to successfully adapt to the environment, the metabolic processes proceed more quickly and efficiently.
cytoplasmic membrane separates the inner contents of the bacterial cell.But much more important than its contribution to the maintenance of a constant internal environment, because due to the osmotic pressure processes can not go in the right direction, and the membrane resists this natural process.A unique feature that is always mentioned, speaking about the structure of the bacterial cell is a cell wall, which is composed of a substance called peptidoglycan.It is porous and allows many solutions to the membrane.Some bacteria have a cell wall (Mycoplasma), but this is an exception.Therefore, antibiotics penicillin and cephalosporin antibiotic-violating cell wall synthesis, effective against bacterial infection.They have no effect on mammalian cells because in the latter there is no need in the cell wall.A bacterium without it can survive - it's their exoskeleton and a barrier against hazards.
Depending on the resistance to staining by Gram gram-positive bacteria divide on (blue after staining) and Gram-negative (pink).In gram-positive bacterial peptidoglycan contain a lot of polysaccharide structures, while Gram-negative layer is very thin, and outside there is the outer shell of phospholipids.
In bacteria, the kernel is not allocated to the membrane, all the processes of reproduction of DNA transcription and translation take place directly among other organelles.DNA is not laid with the help of histones, and is located in the mysterious supercoiled form.Also, in the transfer of genetic material involved plasmids special formation in the cytoplasm.They are not the most important information, but may give an advantage to the owner.Dispatched when horizontal propagation.Simply put, who would get them a cell divides into two - and that was lucky.
The cell also contains a ribosome, which in all the cells of living organisms synthesize protein.In this regard, the bacteria - no exception.The structure of the bacterial cells are also characterized by the fact that most of the bacteria have internal membranes which would delimit the different compartments of the cell.Exception - some phototrophs and bacteria that oxidize methane.
The bacteria can be stored in the form of glycogen carbon and sulfur in the form of granules and nitrogen in the form of nitrates.Also bacteria living in the water, there are gas bubbles that allow them to stay on the surface.Some species have special organelles - Carboxysome (record of atmospheric carbon dioxide) and magnetosomes - oriented bacterium in a magnetic field (for which - a mystery).
are unique special outer protein formation of bacteria - pili, by which bacteria attach to surfaces.Also interesting flagella, allowing them to move in space.
World bacteria waiting inquisitive researchers.And the other is no longer a task stumped: "Describe the structure of the bacterial cell."
