Membrane Transport and the Sodium-Potassium Pump

The Na+/K+-ATPase pumps 3 Na+ out and 2 K+ into the cell per ATP hydrolyzed. (a) Calculate the free energy required to transport 3 mol Na+ from inside (10 mM) to outside (145 mM) against the concentration gradient at 37°C, given a membrane potential of -70 mV (inside negative). (b) Calculate the free energy required for 2 mol K+ transport inward. (c) Is one ATP hydrolysis (ΔG = -50 kJ/mol under cellular conditions) sufficient? (d) How would ouabain affect this pump? (e) Explain the relationship between the Na+/K+ pump and secondary active transport.