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 first two substances are known to kill harmful bacteria such as Staphylococcus aureus and Escherichia coli, by damaging the microbes' cell membranes. —Ben Coxworth, New Atlas, 4 Oct. 2024

Some molecules cross cell membranes passively, while others require specific carriers called transporters. —Merve Ceylan, Health, 23 Sep. 2024

And sometimes a cell membrane pinches off to release chemicals into the environment and then fuses back together again. —Quanta Magazine, 9 Sep. 2024

It was known that lipids are sensitive to pressure, so cell membranes were a prime target for investigation. —Quanta Magazine, 9 Sep. 2024

Word History

First Known Use

1840, in the meaning defined above

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