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The bacterial capsule is a large structure common to many bacteria. [1] It is a polysaccharide layer that lies outside the cell envelope, and is thus deemed part of the outer envelope of a bacterial cell. It is a well-organized layer, not easily washed off, and it can be the cause of various diseases. [2][3]
In most bacteria the most numerous intracellular structure is the ribosome, the site of protein synthesis in all living organisms. All prokaryotes have 70S (where S= Svedberg units) ribosomes while eukaryotes contain larger 80S ribosomes in their cytosol. The 70S ribosome is made up of a 50S and 30S subunits.
The cell is the basic structural and functional unit of all forms of life. Every cell consists of cytoplasm enclosed within a membrane; many cells contain organelles, each with a specific function. The term comes from the Latin word cellula meaning 'small room'. Most cells are only visible under a microscope.
Most prokaryotes are between 1 μm and 10 μm, but they can vary in size from 0.2 μm (Mycoplasma genitalium) to 750 μm (Thiomargarita namibiensis). Prokaryotic cell structure. Description. Flagellum (not always present) Long, whip-like protrusion that aids cellular locomotion used by both gram-positive and gram-negative bacteria. Cell membrane.
Bacterial secretion systems are protein complexes present on the cell membranes of bacteria for secretion of substances. Specifically, they are the cellular devices used by pathogenic bacteria to secrete their virulence factors (mainly of proteins) to invade the host cells. They can be classified into different types based on their specific ...
Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. [1] This takes place through a pilus. [2][full citation needed] It is a parasexual mode of reproduction in bacteria. A micrograph displaying Escherichia coli undergoing bacterial ...
Slime layer. A slime layer in bacteria is an easily removable (e.g. by centrifugation), unorganized layer of extracellular material that surrounds bacteria cells. Specifically, this consists mostly of exopolysaccharides, glycoproteins, and glycolipids. [1] Therefore, the slime layer is considered as a subset of glycocalyx.
The cell envelope comprises the inner cell membrane and the cell wall of a bacterium. In Gram-negative bacteria an outer membrane is also included. [1] This envelope is not present in the Mollicutes where the cell wall is absent. Bacterial cell envelopes fall into two major categories: a Gram-positive type which stains purple during Gram ...