Phospholipid Bilayer

Definition

The phospholipid bilayer is a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends face outward.

Related terms

Hydrophilic Head: These are water-loving parts of molecules; they tend to be attracted to water due to their polar properties.

Hydrophobic Tail: These are water-fearing parts of molecules; they tend to repel away from water due to their non-polar properties.

Amphipathic Molecule: An amphipathic molecule has both hydrophilic (water-loving) and hydrophobic (water-hating) parts. Phospholipids, which make up the bilayer of cell membranes, are amphipathic.