The movement of this ion to the outside of the neuron is the cause of hyperpolarization.
A class of antidiabetic drugs called sulfonyl-ureas block a protein responsible for transporting this ion out of islet cells. In Drosophila, the Shaker gene is a channel for this ion, and the serum concentration of this ion is notably only 3.5 to 5.0 millimolar, and is elevated in (*) hyperkalemia. The movement of this ion to the outside of the neuron is the cause of hyperpolarization. The bulk of this ion is found in the intracellular space, and through the use of active transport and a namesake ATP-dependent "pump," two of these ions are exchanged for every three sodium ions. For 10 points, name this positive ion of an element commonly found in bananas.
A class of antidiabetic drugs called sulfonyl-ureas block a protein responsible for transporting this ion out of islet cells.
potassium (accept K+; prompt if both sodium and potassium are given, as in sodium/potassium pump)