Biophysics of the Cell Surface This volume concentrates attention on the role of membranes in regulating cellular processes as well as on the interactions of cells with their environment a large field with a great number of applications. To make this task manageable the field is narrowed by introducing the word biophysics into the title. Starting with the molecular aspects of the dynamic structure of the membrane chapters treating phenomenological aspects of membrane electrostatics interfacial stability and membrane elastic energy are presented. In a third part functional aspects are discussed: The role of membrane electric field membrane fusion membrane lysis membrane interactions membrane adhesion and membrane motion.