biological membrane
(rus. мембрана, биологическая otherwise биомембрана)
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lipid bilayer with integrated proteins, that separates the cell from the external environment and/or delimits the inner space of the cells.
Description
A biological membrane is 5 nm thick and consists primarily of phospholipids, i.e. lipid molecules with a charged head and hydrophobic tail composed of fatty acid residues. Phospholipids aggregate tail to tail in aqueous solution, turning their charged heads to the water with the formation of a two-layer film (bilayer). This phospholipid bilayer surrounds the cell and delimits its inner compartments. The biological membrane isolates the interior of the cell from the outside environment and prevents the mixing of cell content with the extracellular environment. Specific proteins embedded in the membrane form ion channels, carriers and receptors, and mediate cell interaction with the environment.
Illustrations
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Biological membrane structure sketch.
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Author
- Shirinsky Vladimir P.