ABSTRACT
Starting from the single molecule energy and applying the methods
of statistical mechanics, the free energy of a lipid monolayer
(bilayer) is derived in this section (Fournier, 1996; Kralj-Iglicˇ,
2002; Kralj-Iglicˇ et al., 1999, 2006). The local bending energy of
a laterally homogeneous monolayer (bilayer) (see Canham, 1970;
Helfrich, 1973; Landau and Lifshitz, 1997; Petrov and Derzhanski,
1976) is obtained, and an additional contribution due to average
orientational ordering of lipid molecules-that is, the contribution
of the deviatoric bending (Fischer, 1992, 1993)—is derived (Kralj-
Iglicˇ, 2002; Kralj-Iglicˇ et al., 1999, 2006). The average orientational
ordering of anisotropic phospholipids lowers the free energy of the
system; the effect is more pronounced for lipid molecules of larger
anisotropy and stronger membrane curvature anisotropy (see Kralj-
Iglicˇ et al., 2006).
