Question

a red blood cell placed in a hypertonic solution will shrink in a process called crenation. a red blood cell placed in a hypotonic solution will swell and potentially burst in a process called hemolysis. to prevent crenation or hemolysis, a cell must be placed in an isotonic solution such as 0.9% (m/v) nacl or 5.0% (m/v) glucose. this does not mean that a cell has a 5.0% (m/v) glucose concentration; it just means that 5.0% (m/v) glucose will exert the same osmotic pressure as the solution inside the cell, which contains several different solutes. a red blood cell is placed into each of the following solutions. indicate whether crenation, hemolysis, or neither will occur. • solution a: 3.21% (m/v) nacl • solution b: 1.65% (m/v) glucose • solution c: distilled h₂o • solution d: 6.97% (m/v) glucose • solution e: 5.0% (m/v) glucose and 0.9%(m/v) nacl place each solution into the appropriate bin. show instructions a b c d e crenation hemolysis neither

Explanation:

Step1: Recall tonicity rules

Hypertonic solutions have higher solute - concentration than cell, cause crenation. Hypotonic solutions have lower solute - concentration than cell, cause hemolysis. Isotonic solutions have same solute - concentration as cell, cause neither.

Step2: Analyze Solution A

3.21% (m/v) NaCl is hypertonic compared to 0.9% (m/v) NaCl (isotonic for red - blood cells), so crenation occurs.

Step3: Analyze Solution B

1.65% (m/v) glucose is hypotonic compared to 5.0% (m/v) glucose (isotonic for red - blood cells), so hemolysis occurs.

Step4: Analyze Solution C

Distilled H₂O has no solutes, is extremely hypotonic, so hemolysis occurs.

Step5: Analyze Solution D

6.97% (m/v) glucose is hypertonic compared to 5.0% (m/v) glucose (isotonic for red - blood cells), so crenation occurs.

Step6: Analyze Solution E

5.0% (m/v) glucose and 0.9% (m/v) NaCl is isotonic, so neither crenation nor hemolysis occurs.

Answer:

crenation: A, D
hemolysis: B, C
neither: E