Lipid bilayer of biological membrane

The lipid bilayer of biological membranes refers to a double layer of amphipathic lipid molecules (primarily phospholipids, along with cholesterol and glycolipids) that forms the fundamental structural basis of all cellular membranes[1][3][4][6]. The bilayer provides a selectively permeable barrier, separating the interior of the cell (or organelle) from its external environment and maintaining distinct compartments[3][8]. Hydrophilic (water-loving) phosphate head groups face the aqueous environments on either side of the membrane, while hydrophobic (water-fearing) fatty acid tails face inward, avoiding water and forming the membrane’s core[1][6]. The bilayer structure is fluid, allowing both lipids and membrane proteins to diffuse laterally, which is critical for membrane function, fusion, and protein interactions[4][6]. Lipid bilayers are not considered therapeutic targets themselves; rather, they provide the structural matrix within which biological targets (e.g., receptors, ion channels, transporters) reside. Some drugs interact with the lipid bilayer non-specifically (e.g., by altering membrane fluidity), but the bilayer is not a canonical drug target and lacks a standardized abbreviation or direct clinical target designation[1][4]. The bilayer also anchors and organizes membrane proteins, facilitates cell signaling, regulates molecular traffic, supports membrane fusion processes, and defines the boundaries of cells and organelles[1][4][5].

Other names

Lipid bilayerPhospholipid bilayerBiological membrane lipid bilayer