Membranes are very thin and highly flexible sheets of
molecules which provide the basic structural elements for the
molecular architecture of biological cells, see
membrane cartoons. Even though the molecular composition of biomembranes
is rather complex and highly specific, they all
exhibit the same universal construction principle: a molecular bilayer of
lipids and membrane proteins.
Large membranes form closed compartments and
vesicles, which can be directly observed under the optical
microscope. In eukaryotic cells, these compartments are continuously remodelled:
new compartments are created by membrane budding and fission processes
whereas adhesion and fusion integrate two compartments into a single one.
The self-organization of membranes and vesicles involves many length and time scales.
The following list of membrane topics is roughly ordered from small to large scales:
Recent research on membranes and vesicles includes
the binding constant of membrane-anchored receptors and ligands,
aqueous phase separation within vesicles, and
membrane tension arising from spontaneous curvature.