Biological membrane

See also: Membrane

A biological membrane or biomembrane is an enclosing or separating channels.

Function

Such membranes typically define enclosed spaces or compartments in which cells may maintain a peroxides, and the plasma membrane separates a cell from its surrounding medium. Most organelles are defined by such membranes, and are called membrane-bounded organelles.

Probably the most important feature of a biomembrane is that it is a selectively permeable structure. This means that the size, atoms and molecules attempting to cross it will determine whether they succeed to do so. Selective permeability is essential for effective separation of a cell or organelle from its surroundings. Biological membranes also have certain mechanical or elastic properties.

If a particle is too large or otherwise unable to cross the membrane by itself, but is still needed by a cell, it could either go through one of the protein channels, or be taken in by means of endocytosis.

Types of biological membranes

Cell membrane
Mucous membrane
S-layer