plasma membrane


plasma membrane
plasma membrane n a semipermeable limiting layer of cell protoplasm consisting of a fluid phospholipid bilayer with intercalated proteins called also cell membrane, plasmalemma

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the structure enveloping a cell, enclosing the cytoplasm and forming a selective permeability barrier; it consists of a lipid bilayer with integral and peripheral proteins and contains channels and pumps to transport substances across the membrane, as well as receptors to receive stimuli from the external environment and transduce them into intracellular signals. See Plate 12. Called also cell m., cytoplasmic m., and plasmalemma.

Medical dictionary. 2011.