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

Using salt as his guidestar, Welsh first discovered that a healthy CFTR protein created a chloride channel, which acts as a little pipe through a cell membrane. —Courtney Crowder, USA Today, 18 Apr. 2026

Magnesium helps regulate heart rhythm by supporting the movement of calcium and potassium across cell membranes, Lindsay-Adler said. —Mira Miller, Verywell Health, 14 Apr. 2026

Working with mice, his team focused on a protein called PIEZO2 that converts pressure on cell membranes into nerve signals. —Jacek Krywko, Scientific American, 10 Apr. 2026

Both effects probably result from damaged or rearranged cell membranes. —Matthew Cordes, The Conversation, 6 Apr. 2026

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