A double-layer of
amphipathic lipid molecules arranged with their
nonpolar hydrocarbon tails facing inward. These bilayers can spontaneously form under certain conditions; the
plasma membranes of
animal cells are formed mainly from
phospholipid (
phosphate-containing lipids) bilayers.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.