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

Small molecules are organic compounds with a low molecular weight that are often used in drug development because of their ability to pass through cell membranes and interact with proteins inside the cell. —Paul McClure 11, New Atlas, 11 May 2025

Shiseido is working to future proof its suncare using molecules extracted from the cell membrane of bacteria to filter out the harmful rays of the sun. —Stephanie Hirschmiller, Forbes, 23 Dec. 2024

Textbook diagrams portray cell membranes as thin, passive sheets of insulation wrapped around pipelike nerve fibers. —Douglas Fox, Scientific American, 1 Apr. 2018

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

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