Read the following scenarios and indicate which of the following processes they describe.
1. Sodium ions (Na ) move through sodium channels in a synthetic membrane.
2. Sodium molecules move randomly around a solution of sodium chloride in water, frequently colliding with other sodium ions and chloride ions.
3. Water molecules move into the cytosol of a cell placed in a hypotonic solution.
4. Water molecules move into the cytosol of a cell placed in pure water.
5. The action of sodium-potassium pumps moves sodium ions (Na ) out of a cell and potassium ions (K ) into a cell. The action of sodium-potassium pumps moves sodium ions (Na ) out of a cell and potassium ions (K ) into a cell. The action of sodium-potassium pumps moves sodium ions (Na ) out of a cell and potassium ions (K ) into a cell.
6. Glucose molecules move into cells lining the intestine against their concentration gradient driven by the movement of sodium ions (Na ) into the cells down their concentration gradient.