5 - ns performed molecular dynamics simulation of the hydrated membrane in the liquid crystal phase formed by dimyrystynowej phosphatidylcholine ( DMPC ) and cholesterol ( Chol ) . The aim of the analysis was to clarify the trajectory obtained the mechanism of the ordering and condensing Chol at the atomic level . Ordering of the hydrocarbon chains in the membrane DMPC - Chol is greater than in pure DMPC membrane . Most are arranged adjacent molecular chains of DMPC and Chol smooth surface . In this group the decrease in both the gauche conformation / chain and chain angle with respect to the normal to the film surface . Molecular chains adjacent a rough surface of Chol were less ordered than the surface of the adjacent molecules for the effect of a condensing responsible growth Chol van der Waals interactions between the hydrocarbon chains of DMPC , and not the chains and the interactions between the steroid ring Chol .