Distinguish between a micelle, a bilayer, and a liposome. What are the forces that maintain these structures? Solution Liposomes are composed of a lipid bilayer separating an aqueous internal compartment from the bulk aqueous phase. Micelles are closed lipid monolayers with a fatty acid core and polar surface, or polar core with fatty acids on the surface (inverted micelle). A lipid bilayer is also termed as a bimolecular sheet in which the hydrophobic tails of each individual plane interact with one another, constituting a hydrophobic core which acts as a permeability barrier. Micelle is a smaller structure, generally less than 20 nm (200 Å) in diameter. But a bilayer sheet can be of larger dimensions, e.g. a millimeter (106 nm or 107 Å). Vander wall forces, electrostatic and hydrogen-bonding attractions between the polar head groups and water molecules maintain the structures ..