On the applicability of ising and other statistical models to phase transition in biomembranes

The current literature is critically examined as regards to the applicability of statistical mechanics to the dipole model in order to describe phase transition in biological membranes. The numerical calculations in this context are shown to be speculative and model dependent. Implications of the X-ray diffraction studies on membranes are discussed and it is deduced that only the perpendicular orientation of the dipoles in the polar layer is consistent with the X-ray diffraction data.The author wishes to thank Drs. L. David Roper and E. Keith Hege for many helpful comments.