Fig. 7.

Spectral analysis of bending fluctuations of bilayers at rest, based on conventional MD simulations. Only the 800- and 1800-lipid bilayers in Table 1 were considered (and analyzed together), as the 200-lipid bilayers do not sample adequately the first term of Eq. 5. A) POPC and POPC/CHOL bilayers (${}^{**}P=0.002$). B) DOPC and DOPC/CHOL bilayers ($P=0.24$). Solid lines are best fits of the function in Eq. 5, with shaded bands indicating the 95% confidence interval (CI). P-values are for comparisons of $k_c$ with and without cholesterol. For comparison, dashed bands show the 95% CI for POPC and DOPC under the $q^{-4}$ long-wavelength Helfrich–Canham theory (37, 38), using published values of $k_c$ (27).