membrane

American  

[mem-brayn] / ˈmɛm breɪn /

noun

• membranes
  plural

1. Anatomy. a thin, pliable sheet or layer of animal or vegetable tissue, serving to line an organ, connect parts, etc.

2. Cell Biology. the thin, limiting covering of a cell or cell part.

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membrane British  

/ ˈmɛmbreɪn /

noun

1. any thin pliable sheet of material

2. a pliable sheetlike usually fibrous tissue that covers, lines, or connects plant and animal organs or cells

3. biology a double layer of lipid, containing some proteins, that surrounds biological cells and some of their internal structures

4. physics a two-dimensional entity postulated as a fundamental constituent of matter in superstring theories of particle physics

5. a skin of parchment forming part of a roll

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membrane Scientific  

/ mĕm′brān′ /

1. A thin, flexible layer of tissue that covers, lines, separates, or connects cells or parts of an organism. Membranes are usually made of layers of phospholipids containing suspended protein molecules and are permeable to water and fat-soluble substances.

2. See cell membrane

3. Chemistry A thin sheet of natural or synthetic material that is permeable to substances in solution.

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Other Word Forms

Derived Forms

• intermembrane
  adjective
• membraneless
  adjective

Inflected Forms

Nouns

• membranes
  plural

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Etymology

Origin of membrane

1375–1425; late Middle English; Middle English membraan parchment < Latin membrāna. See member, -an

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Explanation

A membrane is a thin layer of something. For an example of a membrane, you don’t have to look far: your skin is a kind of membrane. Membranes are thin and flexible, but usually still strong enough to protect what’s inside or underneath them. Biologists often study membranes, such as those that surround your cells and organs. There are also membranes that don’t have anything to do with biology. A high-tech jacket might have a waterproof membrane to keep you dry in the rain.

Example Sentences

See Examples For:

membrane membranes

The membrane could instead be installed as a modular filtration system that processes crude oil before it enters conventional distillation equipment.

From Science Daily ● Nov. 5, 2026

The discovery was especially surprising because the buildup of material inside membrane pores, known as fouling, is normally considered a serious problem.

From Science Daily ● Nov. 5, 2026

Nevertheless, the findings suggest that membrane filtration could become a practical way to improve the efficiency of existing facilities.

From Science Daily ● Nov. 5, 2026

The toxin appears to be an exceptionally small protein that inserts itself into the bacterium's surrounding cell membrane.

From Science Daily ● Oct. 31, 2026

She had a soft landing on a warm bouncy surface and was feeling lucky—until she opened her eyes and found herself staring through a glowing gold membrane at another, much larger face.

From "The House of Hades" by Rick Riordan

One early step occurs when stressed cell membranes release arachidonic acid, a fatty molecule that serves as the starting material for producing 5-oxoETE.

From Science Daily ● Nov. 5, 2026

This approach could provide a more affordable and versatile alternative to conventional membranes that require precisely manufactured surface coatings.

From Science Daily ● Nov. 5, 2026

DHA is a major component of brain cell membranes, helping maintain the structure and function of neurons.

From Science Daily ● Oct. 22, 2026

Mitochondria produce energy by maintaining an electrical and chemical difference across their inner membranes.

From Science Daily ● Oct. 21, 2026

The rainwater would seep down gently and the delicate membranes would not be crushed or broken before the emergence of tiny fingers, roots, and leaves pressing out in all directions.

From "Ceremony:" by Leslie Marmon Silko

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Related Words

• sheath
• sheet

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