title: Effective tension and fluctuations in active membranes.
abstract: We calculate the fluctuation spectrum of the shape of a lipid vesicle or cell exposed to a nonthermal source of noise. In particular, we take constraints on the membrane area and the volume of fluid that it encapsulates into account when obtaining expressions for the dependency of the membrane tension on the noise. We then investigate three possible origins of the nonthermal noise taken from the literature: A direct force, which models an external medium pushing on the membrane, a curvature force, which models a fluctuating spontaneous curvature, and a permeation force coming from an active transport of fluid through the membrane. For the direct force and curvature force cases, we compare our results to existing experiments on active membranes.
authors.affiliation: Department of Physics, MEMPHYS-Center for Biomembrane Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense M, Denmark.
authors.forename: Bastien
authors.initials: B
authors.lastname: Loubet
authors.forename: Udo
authors.initials: U
authors.lastname: Seifert
authors.forename: Michael Andersen
authors.initials: MA
authors.lastname: Lomholt
mesh_terms: D002462:Cell Membrane / Q000737:chemistry* / Q000648:ultrastructure*; D003198:Computer Simulation; D008560:Membrane Fluidity; D008956:Models, Chemical; D008958:Models, Molecular; D013500:Surface Tension; D053835:Unilamellar Liposomes / Q000737:chemistry*
chemical_list: D053835:Unilamellar Liposomes