Search results
Results from the WOW.Com Content Network
The cell walls fluoresce to a vivid blue color. Calcofluor-white or CFW is a fluorescent blue dye used in biology and textiles. It binds to 1–3 beta and 1–4 beta polysaccharides of chitin and cellulose that are present in cell walls on fungi, plants, and algae.
A plant cell wall was first observed and named (simply as a "wall") by Robert Hooke in 1665. [3] However, "the dead excrusion product of the living protoplast" was forgotten, for almost three centuries, being the subject of scientific interest mainly as a resource for industrial processing or in relation to animal or human health.
Gram-positive bacteria have a thick mesh-like cell wall made of peptidoglycan (50–90% of cell envelope), and as a result are stained purple by crystal violet, whereas gram-negative bacteria have a thinner layer (10% of cell envelope), so do not retain the purple stain and are counter-stained pink by safranin. There are four basic steps of the ...
A number of other bacteria—that are bounded by a single membrane, but stain gram-negative due to either lack of the peptidoglycan layer, as in the mycoplasmas, or their inability to retain the Gram stain because of their cell wall composition—also show close relationship to the gram-positive bacteria.
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 acidity of the dyes causes them to bind more strongly to the cell walls of the bacteria than to other cells or tissues. This results in the selective staining of only those cells that have a high density of cell wall material, such as acid-fast bacteria. [27] The Ziehl-Neelsen stain is a two step staining process. In the first step, the ...
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 ...
The cell wall is important for cell division, which, in most bacteria, occurs by binary fission. This process usually requires a cell wall and components of the bacterial cytoskeleton such as FtsZ. The ability of L-form bacteria and mycoplasmas to grow and divide in the absence of both of these structures is highly unusual, and may represent a ...