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

The fossil chemicals in question are a special types of steranes, which are the geologically stable form of sterols, like cholesterol, that are found in the cell membranes of complex organisms. —Maria Azzurra Volpe, MSNBC Newsweek, 1 Oct. 2025

Immune System Support Omega-6 fatty acids influence immune function involved in inflammatory responses, strengthening immune cell membranes. —Amy Brownstein, Verywell Health, 1 Oct. 2025

This network of reactions could yield lipids, too—molecules that can arrange themselves into cell membranes. —Jacek Krywko, Scientific American, 30 Sep. 2025

Choline is a nutrient that supports important functions in the body, like facilitating a healthy metabolism and building cell membranes. —Merve Ceylan, Health, 26 Sep. 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