plasma membrane
noun
: a semipermeable limiting layer of cell protoplasm consisting of a fluid phospholipid bilayer with intercalated proteins
called also cell membrane
see cell illustrationExamples of plasma membrane in a Sentence
Recent Examples on the Web
Instead, its photosystems stud the cell’s external plasma membrane rather than the thylakoid membrane found in plants and modern cyanobacteria.
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Quanta Magazine, 10 June 2026
The function of ion channels is to allow specific inorganic ions – primarily sodium (Na+), potassium (K+), calcium (Ca2+), or chloride (Cl-) – to pass in and out of a cell through the plasma membrane.
—New Atlas, 13 Oct. 2024
Upon activation by the caspase-1 protein, gasdermin-D protein assemble to form pores in the plasma membrane of a cell.
—William A. Haseltine, Forbes, 1 July 2022
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Quanta Magazine, 10 June 2026
The function of ion channels is to allow specific inorganic ions – primarily sodium (Na+), potassium (K+), calcium (Ca2+), or chloride (Cl-) – to pass in and out of a cell through the plasma membrane.
—New Atlas, 13 Oct. 2024
Upon activation by the caspase-1 protein, gasdermin-D protein assemble to form pores in the plasma membrane of a cell.
—William A. Haseltine, Forbes, 1 July 2022
Cite this Entry
“Plasma membrane.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/plasma%20membrane. Accessed 16 Jun. 2026.
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