The sodium-potassium pump
maintains high concentrations of Na+
outside the cell and K+
inside the cell, against their concentration gradients.
- 3 cytoplasmic Na+
bind to the pump.
donates a phosphate
group for energy.
- The protein changes its shape, expelling Na+
to the outside.
- 2 extracellular K+
bind to the pump, releasing the phosphate.
- The pump resumes its original shape.
is released inside.