Answer:
In this scenario with a selectively permeable membrane that allows water particles to pass through but not protein particles, water particles will move through the membrane by osmosis from the side with a lower solute concentration to the side with a higher solute concentration. This movement occurs in an attempt to equalize the solute concentration on both sides of the membrane.
Here's a detailed explanation:
1. **Selective Permeability:** The selectively permeable membrane only permits the passage of water molecules (a solvent) while blocking larger molecules like proteins (solute).
2. **Concentration Gradient:** If one side of the membrane has a higher concentration of solute (e.g., salts or other dissolved particles), and the other side has a lower solute concentration, a concentration gradient exists.
3. **Osmosis:** Water molecules will move through the membrane via osmosis, which is the passive movement of water from an area of lower solute concentration to an area of higher solute concentration.
4. **Equilibrium:** This movement continues until equilibrium is reached, which means that the solute concentration on both sides of the membrane becomes equal.
So, water particles will move through the selectively permeable membrane from the side with lower solute concentration (lower concentration of dissolved substances) to the side with higher solute concentration, in an attempt to balance the solute concentrations on both sides. This process of osmosis is vital for maintaining the balance of fluids in biological systems.