A red blood cell with a solvent concentration of 99.1% ?water and a solute concentration of 0.9%NaCl is placed in a beaker with a solvent concentration of 92% ?water and a solute concentration of 8%NaCl. The red blood cell will______
The correct answer and explanation is :
Answer:
The red blood cell will shrink (undergo crenation).
Explanation:
To determine what happens to the red blood cell, we need to analyze the relative concentrations of solute (NaCl) and solvent (water) inside and outside the cell.
Step 1: Understanding Tonicity
- The red blood cell has a solute concentration of 0.9% NaCl and a solvent concentration of 99.1% water.
- The surrounding solution (in the beaker) has a solute concentration of 8% NaCl and a solvent concentration of 92% water.
Since the external environment has a higher solute concentration (8% NaCl) compared to the red blood cell’s internal 0.9% NaCl, the external solution is considered hypertonic to the cell.
Step 2: Osmosis and Water Movement
Osmosis is the movement of water across a selectively permeable membrane from an area of higher water concentration to lower water concentration.
- Inside the cell: 99.1% water
- Outside the cell: 92% water
Because the water concentration is higher inside the cell than in the surrounding solution, water moves out of the cell into the hypertonic solution to balance the solute concentration.
Step 3: Effects on the Red Blood Cell
As water leaves the red blood cell:
- The cell loses water, decreasing in volume.
- The membrane wrinkles and shrinks, a process called crenation.
- The cell may become dysfunctional as its shape is distorted.
Conclusion
In a hypertonic solution (like the 8% NaCl solution in this case), a red blood cell will shrink (crenate) due to water loss. This can negatively impact its ability to transport oxygen efficiently.