The sodium-potassium pump functi- oning in a cell is responsible for the transport of the following ions across the membrane:

Answer options

1. Sodium ions out of the cell, potassium ions into the cell
2. Sodium ions into the cell, chlorine ions out of the cell
3. Calcium ions into the cell, potassium ions out of the cell
4. Sodium ions into the cell, potassium ions out of the cell
5. Chlorine ions into the cell, potassium ions out of the cell