||"Throughout the biological world, a 30 Å hydrophobic film typically delimits the environments that serve as the margin between life and death for individual cells. Biochemical and biophysical findings have provided a detailed model of the composition and structure of membranes, which includes levels of dynamic organization both across the lipid bilayer (lipid asymmetry) and in the lateral dimension (lipid domains) of membranes." See Chiako Sato & Shuji Yonei, Membrane changes, in Perspectives on mammalian cell death. C. S. Potten (ed.). Oxford Scientific Publications, Oxford, 1987. P.1 2nd paragraph:"Figure 1.1 shows a schematic model of the cell surface structure. The central core structure is composed of a lipid bilayer of 50 Å thickness also containing intrinsic proteins. Lipid and protein are present in about equal proportions."