Question

1. Calculate the free energy of transport (Gt) for the movement of sodium ions (Na+ ) from the extracellular space into the cell under the following conditions: [Na+ ]out = 140 mM; [Na+ ]in = 12.0 mM;  =−60.0 mV; T = 37.0C. Use R = 8.314 J/mol K; F = 96,500 J/V mol.

2. Calculate the free energy of transport (Gt) for the movement of potassium ions (K+ ) from the extracellular space into the cell under the following conditions: [K+ ]out = 4.50 mM; [K+ ]in = 145 mM;  =−60.0 mV; T = 37.0C. Use R = 8.314 J/mol K; F = 96,500 J/V mol.

3. The sodium-potassium ATPase pumps 3 moles of Na+ out of the cell and 2 moles of K+ into the cell for every mole of ATP hydrolyzed to ADP and Pi . Using the values you calculated above, and assuming that the free energy of hydrolysis of ATP is – 50.5 kJ/mol, what is the net free energy change associated with the activity of the sodium-potassium ATPase? Is this process thermodynamically favorable under these conditions?

Answer 1

The process is favorable