Elasticidad de las membranas biol\'ogicas

TL;DR

This paper reviews the elastic properties of biological membranes, focusing on the Helfrich model, measurement methods, and physical phenomena like phase transitions and membrane interactions.

Contribution

It presents a comprehensive review of the Helfrich model for membrane elasticity and discusses experimental methods to measure membrane rigidity.

Findings

Helfrich model provides a quantitative description of membrane elastic energy.

Micropipette Manipulation technique can measure membrane rigidity.

Physical phenomena such as phase transitions and steric interactions are explained by elasticity concepts.

Abstract

In this article we review the present knowledge on the elastic properties of membranes of biological origin. Assuming the fluid mosaic hypothesis, we consider the phospholipid bilayer as the structural base of a biological membrane. We expose a model due to Helfrich which can be used to obtain an expression for the membrane elastic energy. The free energy is completely characterized by two local principal curvatures and four parameters that depend on the chemical composition of the membrane and its local environment. In addition we present the theoretical justification of an experimental method (the Micropipette Manipulation technique) that may be used to measure the membrane rigidity. Finally, we describe some physical consequences of these concepts, such as the explanation of the lamellar-sponge phase transition and the emergence of the steric interaction between membranes. ------ Se presenta una revisi\'on del conocimiento actual sobre las propiedades el\'asticas de las membranas. Bajo la hip\'otesis del mosaico fluido se considera a una bicapa de fosfol\'ipido como la base estructural de una membrana biol\'ogica y se expone un modelo debido a Helfrich a partir del cu\'al se obtiene una expresi\'on para la energ\'ia el\'astica de una membrana. La energ\'ia libre queda completamente caracterizada por sus curvaturas locales principales y cuatro par\'ametros dependientes de la composici\'on qu\'imica de la membrana y de su entorno local. Se expone la justificaci\'on te\'orica de un m\'etodo experimental que permite medir la constante el\'astica de curvatura media de una membrana. Finalmente se describen algunas consecuencias f\'isicas de estos conceptos, como la explicaci\'on de la transici\'on de una fase lamelar a una esponja, o la aparici\'on de la interacci\'on est\'erica entre membranas.