Lipids associate with one another via van der Waals forces and the hydrophobic effect.
Soaps are the sodium or potassium salts of long-chain fatty acids.
Detergents form micelles , which are spherical bodies with hydrophilic portion of the molecules on the outside and the hydrophobic portion on the inside. Triglycerides are stored as a reserve of metabolic energy in fat cells and in the seeds of plants. None of the lipids mentioned above are components of membranes. Liposomes consist of an enclosed liquid volume surrounded by a spherical bilayer, and they are often used by biochemists for reconstitution studies of purified membrane proteins. Membranes are made up of a variety of types of lipids, including glycerophospholipids, sphingolipids, and cholesterol.