Cell membrane

Cell Membrane

The Cell Membrane (pronunciation: /sɛl ˈmɛmbreɪn/), also known as the plasma membrane, is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells.

Etymology

The term "cell membrane" is derived from the Latin word 'cella' meaning a small room and the Latin 'membrāna' meaning a thin skin or film. The term was first used in the 19th century to describe the thin layer that enclosed the cell.

Structure

The cell membrane is composed primarily of lipids, proteins, and carbohydrate molecules. The most abundant lipids in most cell membranes are phospholipids. Other lipids are cholesterol and glycolipids.

Function

The cell membrane serves several functions. It provides a barrier between the cell and its environment, controls the passage of substances into and out of the cell, and communicates with other cells. It also plays a role in cell adhesion and signal transduction.

Related Terms

Phospholipid bilayer: The basic structure of the cell membrane, composed of two layers of phospholipids.
Lipid rafts: Microdomains within the cell membrane that contain high concentrations of cholesterol and glycosphingolipids.
Fluid mosaic model: A model that describes the structure of cell membranes as a mosaic of lipid molecules that act as a solvent for all the substances and proteins within it.
Membrane transport: The process of transport of substances across a cell membrane.
Cell wall: A structural layer surrounding some types of cells, situated outside the cell membrane.