In the example above Na^+ and K^+ are penetrating solutes, meaning they can freely pass through the membrane. These are also termed crystalloids. Albumin in the example is a non-penetrating solute (cannot pass through the membrane). These non-penetrating solutes are also called colloids. Is the movement of water in the example above due to concentration differences in cystalloids or colloids? Osmotic force is the force (or pressure) that causes osmosis. In your own words, define osmotic force in terms of differences in solute concentration between two compartments (be specific per your answer to question 3). What would cause osmotic force to increase/decrease?