Oil molecules in a monolayer are oriented so polar head groups are in contact with water , whereas their nonpolar lipid moieties project into air . Phospholipids and Glycolipids Form Bimolecular Sheets in Aqueous Media Polar head groups of phospholipids and glycolipids like to be in contact with water . Their hydrocarbon tails will try to avoid water . Form a micelle or form a bimolecular sheet , which is also called a lipid bilayer . Favored structure is a bimolecular sheet rather than a micelle.
Sheets are quite fluid .
Bimolecular sheet is inherent in the structure of its constituent lipid molecules . Lipids and Many Membrane Proteins Diffuse in the Plane of the Membrane Biological membranes are not rigid . Lipids and many membrane proteins constantly in lateral motion . Movement of membrane proteins visualized by means of fluorescence microscopy . Human cells and mouse cells fuse resulting in a cell called a heterokaryon .