sodium pump
noun
1
: a molecular mechanism by which sodium ions are transferred across a cell membrane by active transport
especially : one that is controlled by a specialized plasma membrane protein by which a high concentration of potassium ions and a low concentration of sodium ions are maintained within a cell
2
: the specialized plasma membrane protein that controls the sodium pump mechanism
Example Sentences
Recent Examples on the Web Some flies had one mutation of three seen in the sodium pump gene of monarchs, and some had combinations. 
Tim Vernimmen, Scientific American, 2 Oct. 2019 First, a mutation of small effect would have altered the structure of the sodium pump to provide some resistance, but also some neurological problems. Tim Vernimmen, Scientific American, 2 Oct. 2019
Tim Vernimmen, Scientific American, 2 Oct. 2019 First, a mutation of small effect would have altered the structure of the sodium pump to provide some resistance, but also some neurological problems. Tim Vernimmen, Scientific American, 2 Oct. 2019 Word History
First Known Use
1951, in the meaning defined at sense 1
Medical Definition
sodium pump
noun
1
: a molecular mechanism by which sodium ions move across a cell membrane by active transport
especially : one by which a high concentration of potassium ions and a low concentration of sodium ions are maintained within a cell and that is controlled by a specialized plasma membrane protein linking the hydrolysis of ATP to the active transport of intracellular sodium ions out of the cell and extracellular potassium ions into the cell to create an electrical and chemical gradient across the cell membrane necessary for vital cell functions (as nerve cell excitation and cell volume regulation)
2
: the specialized cell membrane protein that controls the sodium pump mechanism