Ecoli Bacteria Structure
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E. coli is a bacterium which can be harmful to the human body under certain circumstances. E. coli is a type of gram-negative bacteria that is rod-shaped.
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The essential structural components of E. coli bacteria include appendages (adhesive fimbriae which aid in the adherence of bacteria to cell or tissue surface or substrates), cell envelope and the capsule, cell wall and plasma membrane and an inner cytoplasmic region that houses the genetic materials such as cell chromosome (DNA) and ribosomes and other inclusions.
The cell wall is thin and multilayered, consisting of a relatively thin peptidoglycan sheet between the plasma membrane and a phospholipid-lipopolysaccharide outer membrane. The Peptidoglycan structure and arrangement is made up of alternating molecules of N-acetylglucosamine (G) and N-acetylmuramic acid (M) connected by a beta 1, 4-glycoside bond. The function of the cell wall is to protect the cell from internal turgor pressure (caused by a high concentration of proteins and inorganic ions) and prevents it from bursting.
The capsule is made up of polysaccharides. The flagellum of E. coli consists of three distinct parts -- the filament, the hook and the basal body -- all of which are made up of different types of proteins. Sandwiched in between the inner plasma membrane and the outer membrane is the periplasm comprising of the peptidoglycan which contains numerous vital enzymes.
The cytoplasmic membrane is composed of a phospholipid bilayer and regulates the passage of substances into and out of the cell. Found within the cytoplasmic membrane is the cytoplasm. The cytoplasm contains proteins, RNA, DNA, phospholipids, lipopolysaccharides, murein, glycogen, certain inorganic ions, vitamins, metabolites, etc. Contained in the cytoplasm are the glycogen inclusions, which function as carbon and energy reserves.
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