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 polymer mimics lipids in skin cell membranes and can capture moisture when humidity is high and deliver it back to the skin when the air is drier. —Justin Fenner, Robb Report, 6 Mar. 2026

The duo knew from their previous studies that certain cells in the mouse embryo were tenser and sturdier than others due to differences in their internal scaffolds, which underpin the cell membrane and keep it taut. —Clare Watson, Quanta Magazine, 27 Feb. 2026

According to McFarland, studies dating back to the 1960s, showed that electrical current flows in trees broke down cell membranes and destroyed the chloroplasts that the trees use to photosynthesize—or make food from the sun. —Laura Baisas, Popular Science, 25 Feb. 2026

This creates greater absorption, connecting vitamin C directly to the cell membrane. —Bestreviews, Chicago Tribune, 17 Feb. 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