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. In a 150 mM NaCl solution, the red blood cell would neither shrink nor swell, as the concentration of NaCl is isotonic (equal) to the physiological concentration inside the cell, resulting in no net movement of water.
b. In a 100 mM NaCl plus 50 mM albumin solution, the red blood cell would swell, as the albumin creates an osmotic pressure that draws water into the cell, leading to an increase in volume.