If free phospholipids were swirled into water, they would ____.

A) form pairs
B) form spheres with the phosphate-containing heads facing each other
C) dissolve
D) form a lipid bilayer sheet, with the hydrophobic tails facing each other
E) form a lipid bilayer sheet, with the phosphate-containing facing each other

Phospholipids

A class of lipids that form the main structural component of cell membranes, made up of two fatty acids, a glycerol unit, and a phosphate group.

Lipid Bilayer

Double layer of phospholipids arranged tail-to-tail; structural foundation of all cell membranes.

Hydrophobic Tails

The nonpolar, water-repelling part of a phospholipid molecule that faces inward, away from water, in the bilayer of cell membranes.