plasmalemma

American  

[plaz-muh-lem-uh] / ˌplæz məˈlɛm ə /

noun

Cell Biology.

PLURAL

plasmalemmas

1. cell membrane.

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plasmalemma British  

/ ˌplæzməˈlɛmə /

noun

1. other names for cell membrane

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Usage

What is a plasmalemma? Plasmalemma is a less common term for the cell membrane—the thin layer that encloses a cell’s cytoplasm, which is the substance between the membrane and the nucleus. It allows beneficial things to pass through while blocking harmful ones. It is also called the plasma membrane.The cell is the basic structural unit of all living organisms. It is a microscopic structure consisting of a nucleus surrounded by the cytoplasm and enclosed by a membrane—the plasmalemma. In general, a membrane is a thin barrier or covering. In the context of biology, plasma is used as another word for cytoplasm. The lemma in plasmalemma comes from a Greek word that means “husk.”The membrane consists of a double layer made up of lipid molecules and large protein molecules. Lipids and proteins are the basic building blocks of living cells. They move fluidly in the plasmalemma and function like a system of gates, giving the membrane its ability to allow molecules to pass through. For this reason, the membrane is described as semipermeable (meaning it is capable of allowing things to pass through it).Plants cells also have a rigid outer wall in addition to a plasmalemma.

Etymology

Origin of plasmalemma

1920–25; plasma + Greek lémma husk ( lemma ² )