3 Na+ ions attach to the transporter. ATP hydrolyzes, releasing a phosphate which binds to the transporter, causing a conformational change that releases the Na+ ions and phos
…phate to the cytosol. The decrease in Na+ ions causes an electrochemical gradient in the cell which attracts the K+ ions to the transporter which are brought in passively due to the electrochemical gradient. This maintains the membrane potential and osmotic pressure of the cell. (MORE)