Biological Membranes and transport Biological membranes are made of a lipid bilayer decorated with various proteins and/or carbohydrates Membranes define the external boundaries of cells and requlate the molecular traffic across that boundary In eukaryotic cells, membranes also divide the internal space into discrete compartments to segregate processes and componentsBiological Membranes and Transport • Biological membranes are made of a lipid bilayer decorated with various proteins and/or carbohydrates. • Membranes define the external boundaries of cells and regulate the molecular traffic across that boundary • In eukaryotic cells, membranes also divide the internal space into discrete compartments to segregate processes and components