Predict what would happen to a red blood cell placed in each of the following external solutions. Would it shrink, swell, or not change its volume? Explain each answer in ONE sentence.
a. 150 mM NaCl b. 100 mM NaCl plus 50 mM albumin
a. If a red blood cell is placed in a solution of 150 mM NaCl, it would not change its volume because the solution concentration is isotonic to the cell, resulting in no net movement of water across the plasma membrane.
b. If a red blood cell is placed in a solution of 100 mM NaCl plus 50 mM albumin, it would swell because the solution has a lower solute concentration than the cell, resulting in water moving into the cell by osmosis and causing it to increase in volume.