Na K+ ATPase carrier protein located on the plasma membrane of all cells plays an important role in regulating osmotic balance by maintaining Nat and K balance inhibition b ouabain causes cells to swell and burst requires one to two thirds of cells energy! Functions of Na K Pump Regulation of cell volume fixed anions" attract cations causing osmosis cell swelling stimulates the Na K pump to ion concentration osmolarity and cell swelling Maintenance of a membrane potential in all cells pump keeps inside negative(-ve), outside positive(+ve)