Phospholipids assemble to form

• A. Micelles
• B. Lipid bilayers
• C. Protein networks
• D. Carbohydrate plaques

Answer: (B)

Phospholipids are amphipathic, with hydrophilic heads and hydrophobic tails. In water, they arrange so that the tails are shielded from the aqueous environment while the heads face outward. The two-tail geometry promotes the formation of a stable two-layer sheet, a lipid bilayer, which can seal into closed membranes. This bilayer is the fundamental structure of cell membranes and delineates compartments by providing a continuous, flexible barrier. Micelles can form from lipids with a single tail, but phospholipids with two tails preferentially assemble into bilayers rather than single-molecule micelles. Protein networks involve proteins rather than lipid units, and carbohydrate plaques are not formed by phospholipid assemblies.