cell membrane

/sɛl ˌmɛmˈbreɪn/

Other forms: cell membranes

A cell membrane is like a cell's gatekeeper. It's the outer layer that surrounds a cell, letting substances in — or keeping them out.

A membrane is a barrier that offers protection, like a rubber membrane that keeps rain from seeping under your roof. A cell membrane surrounds and protects the contents of a cell. It controls which substances can enter and exit the cell. The membrane also gives a cell its shape and enables the cell to attach to other cells, forming tissues.

Definitions of cell membrane

1. noun

   a thin membrane (a double layer of lipids) enclosing the cytoplasm of a cell; proteins in the membrane control passage of ions (like sodium or potassium or calcium) in and out of the cell
   “all cells have a cell membrane”

   synonyms: cytomembrane, plasma membrane

   type of:

   semipermeable membrane

   a membrane (as a cell membrane) that allows some molecules to pass through but not others