Question

The sodium potassium pump transports 5 ions for every molecule of ATP that is hydrolyzed: 3 Na+ out of the cell and 2 K+ into the cell. The pump maintains internal Na+ at 11 mM and external Na+ at 144 mM; it maintains internal K+ at 139 mM and external K+ at 7 mM. Assuming that the membrane potential is –69 mV (inside negative relative to outside), the temperature is 37 °C, and F is 23.1 kcal/V·mol, how much energy does it take to run the pump (i.e., how many kcal of energy are required per 5 mol of ions pumped)? Report your answer to the nearest tenth of a unit.