cells and transport

Question

A red blood cell neither gains nor loses water when placed into 0.9% NaCl. Water moves in 

        and out of the cell but there is no net movement of water.  

a) Therefore, it can be said that at this concentration the cell has achieved a dynamic __________________. (1 mark)

b) What term would be used to describe the 0.9% NaCl solution as compared to the red blood cell? ___________________. (1 mark)

 

Imagine the red blood cell is now placed into two different solutions as shown below:

c) Is Solution X hypotonic or hypertonic to the red blood cell? (1 mark)

d) What will happen to the cell in Solution X? Explain why?(1 mark)

e) Is Solution Y hypotonic or hypertonic to the red blood cell? (1 mark)

f) What will happen to the cell in Solution Y? Explain why?(1 mark)

Answer 1

a) Therefore, it can be said that at this concentration, the cell has achieved a dynamic equilibrium.

b) What term would be used to describe the 0.9% NaCl solution as compared to the red blood cell? Isotonic.

c) Solution X is hypotonic to the red blood cell.

d) In Solution X, water will move into the red blood cell. This is because the solution has a lower concentration of solutes (0.001% NaCl) compared to the inside of the cell (which is around 0.9% NaCl). Water moves from an area of lower solute concentration to an area of higher solute concentration, causing the cell to swell or potentially burst due to osmotic pressure.

e) Solution Y is hypertonic to the red blood cell.

f) In Solution Y, water will move out of the red blood cell. This is because the solution has a higher concentration of solutes (15% NaCl) compared to the inside of the cell. Water moves from an area of higher solute concentration to an area of lower solute concentration, causing the cell to shrink or undergo crenation due to the loss of water.