1. Biomembranes are organized, sheetlike assemblies consisting mainly of proteins and lipids 1.1 The functions carried out by membranes are diverse and indispensable for life. 1.1.1 Biomembranes give cells their individuality by separating them from the environment
1. Cells need energy to do all their work To generate and maintain its highly ordered structure (biosynthesis of macromolecules). To generate all kinds of movement. To generate concentration and electrical gradients