Describe the sodium-potassium ion pump on cell plasma membranes (2 marks)
These pumps use ATP / active transport to move 3 sodium ions (Na+) out of the cell for every two potassium ions (K+) that move in.1 mark - idea of active transport / use of ATP1 mark - idea of 3 Na+ and 2K+ AND sodium ions moving in and potassium ions moving out
