1. 2.5All membrane lipids are amphipathic that form bilayer structures spontaneously in aqueous media. 1.2.6 Membranes are cooperative noncovalent assemblies 1.2.7 Membranes are always asymmetric with two different faces 1.2.8 Membranes are fluid two-dimensiona structures(the fluid mosaic model) with oriented proteins and lipids(which form bilayer structures) that can diffuse laterally but not vertically.(fig and video).1.2.5 All membrane lipids are amphipathic that form bilayer structures spontaneously in aqueous media. 1.2.6 Membranes are cooperative noncovalent assemblies. 1.2.7 Membranes are always asymmetric with two different faces. 1.2.8 Membranes are fluid two-dimensional structures (the fluid mosaic model) with oriented proteins and lipids (which form bilayer structures) that can diffuse laterally but not vertically. (fig and video)