plasma membrane

American  

noun

Cell Biology.

1. cell membrane.

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plasma membrane Scientific  

1. See cell membrane

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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

Compare meaning

How does plasma-membrane compare to similar and commonly confused words? Explore the most common comparisons:

• plasma membrane vs. cell membrane

Example Sentences

NRP1 interacts with TrkA and brings it from the interior of the cell to the plasma membrane on the surface.

From Science Daily • Dec. 5, 2024

Free cholesterol is drawn into the cell's plasma membrane -- the external boundary of the cell -- by a protein called NPC1L1.

From Science Daily • Nov. 9, 2023

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 • Oct. 25, 2023

They have no plasma membrane, internal organelles, or metabolic processes, and they do not divide.

From Textbooks • Apr. 25, 2013

When neurotransmitter molecules bind to receptors located on a neuron’s dendrites, the neurotransmitter opens ion channels in the dendrite’s plasma membrane.

From Textbooks • Apr. 25, 2013