![]() ![]() Ribosomes are site of protein synthesis.In prokaryotes, ribosome are attached with cell membrane having two sub-units – 50S and 30S to form together 70S prokaryotic ribosomes.Pili and fimbriae are the other surface structures that help the bacteria to attach with host and other substances. Motile bacterial cell contains flagella, which is composed of filament, hook and basal body.They help in cell wall formation, DNA replication and distribution to daughter cells. Plasma membrane is semi-permeable having mesosome in the form of vesicles, tubules, and lamellae.In some other bacteria, Glycocalyx may be thick and tough called capsule. Glycocalyax may be as loose sheath in some bacteria called slime layer.The outermost is Glycocalyx, middle one cell wall and inner innermost is the cell membrane. In bacterial cell, a chemically complex cell envelope is present, which consist of three layers.A specialized differentiated cell membrane called Mesosome is the characteristic of prokaryotes. Cell organelles like Mitochondria, Golgi bodies etc.The plasmid DNA, in some bacteria, provides some special features like resistance to antibiotics.All prokaryotic cells have cell wall surrounding the cell membrane except in Mycoplasma.Bacterial cells may be Bacillus (rod-shaped), Coccus (spherical), Vibrio (comma-shaped) and Spirillum (spiral).They multiply rapidly and vary in size greatly. Prokaryotic cells are represented by Bacteria, Blue-green algae, Mycoplasma and PPLO.The shape of cell may be cuboid, columnar, polygonal, thread-like or irregular. Mycoplasma is the smallest cell and largest isolated cell is the ostrich egg. Shape and size of cells varies greatly according to their position and function. All cells arise from pre-existing cells.All living organisms are composed of cells and products of cells. ![]()
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