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Since the cell wall is required for bacterial survival, but is absent in some eukaryotes, several antibiotics (notably the penicillins and cephalosporins) stop bacterial infections by interfering with cell wall synthesis, while having no effects on human cells which have no cell wall, only a cell membrane.
The bacterial cell wall differs from that of all other organisms by the presence of peptidoglycan (poly-N-acetylglucosamine and N-acetylmuramic acid), which is located immediately outside of the cytoplasmic membrane. Peptidoglycan is responsible for the rigidity of the bacterial cell wall and for the determination of cell shape. It is ...
Structure of a teichoic acid repeat unit from Micrococcaceae Structure of the lipoteichoic acid polymer. Teichoic acids (cf. Greek τεῖχος, teīkhos, "wall", to be specific a fortification wall, as opposed to τοῖχος, toīkhos, a regular wall) [1] are bacterial copolymers [2] of glycerol phosphate or ribitol phosphate and carbohydrates linked via phosphodiester bonds.
For many bacteria, the S-layer represents the outermost interaction zone with their respective environment. [9] [2] Its functions are very diverse and vary from species to species. In many archaeal species the S-layer is the only cell wall component and, therefore, is important for mechanical and osmotic stabilization.
The cell wall is essential to the survival of many bacteria, although L-form bacteria can be produced in the laboratory that lack a cell wall. [38] The antibiotic penicillin is able to kill bacteria by preventing the cross-linking of peptidoglycan and this causes the cell wall to weaken and lyse. [ 37 ]
Bacillota (synonym Firmicutes) is a phylum of bacteria, most of which have gram-positive cell wall structure. [2] The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature.
Enclosing the cell is the cell envelope, generally consisting of a plasma membrane covered by a cell wall which, for some bacteria, may be further covered by a third layer called a capsule. Though most prokaryotes have both a cell membrane and a cell wall, there are exceptions such as Mycoplasma (bacteria) and Thermoplasma (archaea) which only ...
This causes the bacteria to form filaments, elongated cells that lack internal cross-walls. [10] After a period of time, the cell walls of the filaments are digested, and the bacteria collapse into very large spheres surrounded by just their cytoplasmic and outer membranes.