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

Life incorporates fatty acids into cell membranes and uses them to regulate various cell and organ processes. —Keith Cooper, Space.com, 25 Mar. 2025

Human and mouse cell membranes carry some of the same phospholipids as those in fungi, notes Arun Maji, an expert in drug design at the University of Kentucky. —Bykai Kupferschmidt, science.org, 19 Mar. 2025

Drugs that cross the BBB are typically fat-soluble molecules that diffuse directly through cell membranes, whereas larger or water-soluble molecules face significant challenges. —Jenny Lehmann, Discover Magazine, 26 Feb. 2025

But physicists are starting to realize that cell membranes have surprising properties. —Douglas Fox, Scientific American, 1 Apr. 2018

Word History

First Known Use

1840, in the meaning defined above

Rhymes for cell membrane

• aeroplane
• appertain
• ascertain
• capitaine
• cassegrain
• cellophane
• chatelaine
• counterpane
• entertain
• gethsemane
• halothane
• hurricane

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