plasma membrane
Americannoun
Usage
What is a plasma membrane? Plasma membrane is another 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.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 plasma membrane. In general, a membrane is a thin barrier or covering. In the context of biology, plasma is used as another word for cytoplasm.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 plasma membrane 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 plasma membrane.The plasma membrane is also called the plasmalemma.
Etymology
Origin of plasma membrane
First recorded in 1895–1900
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
From earlier research, the scientists knew that Rnf43 on its own was not sufficient to break down the Wnt receptor Frizzled, which sits in the plasma membrane.
From Science Daily
Free cholesterol is drawn into the cell's plasma membrane -- the external boundary of the cell -- by a protein called NPC1L1.
From Science Daily
Four of the compounds -- including two of the newly identified ones -- were effective at destroying the plasma membrane of this fungus, causing its cells to leak and preventing it from forming biofilms.
From Science Daily
The protein has an intracellular kinase enzyme domain, and an extracellular domain that protrudes into the apoplast — the compartment between a plant cell’s plasma membrane and the cell wall.
From Nature
In neuronal cells, gangliosides directly or indirectly regulate important properties of receptors and ion channels in specific regions of the plasma membrane known as microdomains, which have a distinctive lipid composition9.
From Nature
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