Question

An animal cell placed in a hypertonic solution will shrink in a process called crenation. An animal cell placed in a hypotonic solution will swell and potentially burst in a process called hemolysis. To prevent crenation or hemolysis, an animal 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. Hint : A 5.0% (m/v) glucose solution will exert the same osmotic pressure as a red blood cell. Also, a 0.9% (m/v) NaCl solution will exert the same osmotic pressure as a red blood cell. This means that any solution with a higher total solute concentration than either of these isotonic solutions will be hypertonic to the cell. Conversely, any solution with a lower total solute concentration than an isotonic solution will be hypotonic to the cell. A red blood cell is placed into each of the following solutions. Indicate whether crenation, hemolysis, or neither will occur.

Answer 1

Answer: A = crenation; B = hemolysis; C = hemolysis, D = crenation; E = neither will occur.

Note: The question is incomplete. The complete question is;

An animal cell placed in a hypertonic solution will shrink in a process called crenation. An animal cell placed in a hypotonic solution will swell and potentially burst in a process called hemolysis. To prevent crenation or hemolysis, an animal 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. Hint : A 5.0% (m/v) glucose solution will exert the same osmotic pressure as a red blood cell. Also, a 0.9% (m/v) NaCl solution will exert the same osmotic pressure as a red blood cell. This means that any solution with a higher total solute concentration than either of these isotonic solutions will be hypertonic to the cell. Conversely, any solution with a lower total solute concentration than an isotonic solution will be hypotonic to the cell. 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) NaClSolution B: 1.65% (m/v) glucoseSolution C: distilled H2OSolution D: 6.97% (m/v) glucoseSolution E: 5.0% (m/v) glucose and 0.9%(m/v) NaCl

Explanation:

First the concentrations of the NaCl and glucose solutions that are isotonic with the red blood is determined.

Concentration of 0.9% m/v NaCl = 0.9 g/100cm³ = 9 g/dm³

Concentration of 5.0% m/v glucose = 5 g/100cm³ = 50 g/dm³

Concentration of NaCl in Solution A (3.21% (m/v) = 3.21 g/100cm³

= 32.1 g/dm³

Solution A is hypertonic, therefore, crenation will occur.

Concentration of 1.65% (m/v) glucose Solution = 1.65 g/100cm³ = 16.5 g/dm³

Solution B is hypotonic, therefore, hemolysis will occur.

Solution C,  Distilled water contains no dissolved solutes. The solution is hypotonic, therefore, hemolysis will occur.

Concentration of 6.97% (m/v) glucose solution = 6.97 g /100cm³

= 69.7 g/dm³

The solution is hypertonic. Therefore, crenation will occur.

Concentrations of 5.0% (m/v) glucose and 0.9%(m/v) NaCl are 50 g/dm³ and 9 g/dm³ respectively. Both solutions are isotonic to the red blood cell. Therefore, neither crenation nor hemolysis will occur.