cell membrane

noun

plural cell membranes

: a membrane of a cell

especially : a semipermeable limiting layer of cell protoplasm consisting of a fluid phospholipid bilayer with intercalated proteins : plasma membrane

Despite being much maligned in the popular press, cholesterol plays a crucial role in organizing cell membranes and controlling their physical properties.

—Amanda Yarnell

… a cascade of reactions culminating in the transfer of a phosphate group to a protein complex that carries ions across the cell membrane.

—Science News

Examples of cell membrane in a Sentence

Recent Examples on the Web

Today, the main components of most cell membranes are complex, hefty molecules called phospholipids. —Bymitch Leslie, science.org, 30 Oct. 2024

And sometimes a cell membrane pinches off to release chemicals into the environment and then fuses back together again. —Yasemin Saplakoglu, WIRED, 20 Oct. 2024

For instance, phospholipids in modern cell membranes align themselves in a double layer. —Bymitch Leslie, science.org, 30 Oct. 2024

Life is composed of three distinct cell types: bacteria and archaea, which are both prokaryotic cells with some key differences — for example in their cell membranes and reproductive strategies — and then there are eukaryotes, which are a much different kind of cell. —Quanta Magazine, 28 Oct. 2024

Word History

First Known Use

1840, in the meaning defined above

Kids Definition

cell membrane

noun

: a semipermeable outside layer surrounding the contents of a cell

Medical Definition

cell membrane

noun

: a membrane of a cell

especially : plasma membrane