These are very different from the walls of eukaryotes, which are built mainly with polysaccharides. Peptidoglycan is a mesh-like molecule composed of changes of special sugars crosslinked together by short chains of amino acids. The LPS layer is similar in structure to the lipid bilayer of the plasma membrane. The cell wall is often surrounded by a mucilaginous capsule or sheath. This sheath is sometimes so thick that the cells appear to be embedded in a mass of jelly.
Some species swim by means of flagella Bacterial flagella are analogous to flagella of eukaryotes.
Although superficially similar in that they give the cell the ability to move, they are very different structurally. Cyanobacteria never have flagella. Prokaryotes are vitally important ecologically and economically Most bacteria are important as decomposers Bacteria carry out reactions that influence the environment Nitrogen fixation converts nitrogen gas into a form usable by plants. Some parasitic bacteria cause diseases Bacteria are found in virtually all environments suitable for life. The most plant-like of the the Monera.