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

Inside cells, fat is tucked away in lipid droplets, which act like tiny storage units that house reserve energy but also play a key role in building and repairing cell membranes. —New Atlas, 28 Aug. 2025

The virus then waited until other receptor proteins, moving around in the fluid cell membrane, accumulated nearby. —Katarina Zimmer, JSTOR Daily, 14 Aug. 2025

Some dailies, for example, are coated with phospholipid, which is what cell membranes are made of. —Angela Haupt, Time, 7 Aug. 2025

Melittin works by punching holes on the cell membranes. —Jasmine Laws, MSNBC Newsweek, 5 Aug. 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