Answer to Question #38891 in Biochemistry for IMANI

Question

Red blood cell membranes are completely impermeable to sodium, potassium and chloride ions, however they are permeable to both water and urea. The concentration inside a red blood cell is 300mOsm and consists predominantly of sodium and potassium chloride.
a) With the aid of diagrams, decide what would happen to red blood cells when placed in the following solutions.
i. Fresh water.
ii. Salt solution at a concentration of 300mOsm.
iii. Salt solution at a concentration of 400mOsm. iv. A urea solution at a concentration of 300mOsm.
b) Which solutions were isosmotic to the red blood cells? c) Which solutions were isotonic to the red blo

Answer 1

a) i. water will move into the red bood cells and they will swell and can burst
ii. no changes will happen to red blood cells
iii. water will move out from the cells. They will shrink.
iv. No changes will happen to red blood cells

b) isosmotic to the red blood cells will solution with an equal osmotic pressure.
π = icRT The term ic is the osmolarity of the solution: 0.3 mol/L
π = 0.3 mol/L x 0.082 L•atm/(K•mol) x 310 K = 7,6 atm

c) 300mOsm