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plasma membrane
the membrane that encloses a cell, composed of phospholipids, glycolipids, cholesterol, and proteins. The primary structure is a lipid bilayer. Phospholipid molecules have an electrically charged “head” that attracts water and a hydrocarbon “tail” that repels water. These molecules line up side by side in two opposing layers with their heads on the inner or outer surface of the membrane
and their tails in the core, from which water is excluded. The other lipids affect the structural properties of the membrane.
Proteins embedded in the membrane transport specific molecules across the membrane, act as hormone receptors, or perform other functions.
Copyright 2007. An Elsevier publication. All rights reserved.
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