What is Hypertonic Solution

What is a Hypertonic Solution?

A Hypertonic Solution can be defined as a solution that has higher osmotic pressure due to much higher concentration of solute particles and much lower concentration of water.    

• 1 M NaOH solution is hypertonic compared to 0.05 M urea solution indicating that osmotic pressure of 1 molar NaOH solution shall be greater than the osmotic pressure of 0.05 molar urea solution.

• Compared to freshwater, Seawater is hypertonic due to higher salt particle concentration which is also the reason why freshwater cannot survive in seawater.

Effect of Hypertonic Solution on the cells

The cell membranes are selectively permeable and they allow only certain particles and not others to pass through them. Usually, larger molecules can’t fit through the membrane without specific channels. The cell membrane is fitted with special protein channels called Aquaporins, which allow water molecules to pass through without expending energy. However, the ease with which the water molecules can cross is going to depend on something called the concentration which is the measure of how much solute is there per volume of solvent.

Since hypertonic solution has higher solute concentration, it causes shrinkage if a plant/animal cell is put in a hypertonic solution as the water molecules tend to move from inside to the outside of the cell through the semipermeable membrane to restore equilibrium by equalizing solute particle concentrations both inside and outside of the cell. This causes the cell membrane to shrink and the cell to become turgid due to net outflow of water.

Uses of Hypertonic Solutions

There are several uses of hypertonic solutions like aiding in food preservation, causing the desired dehydration of food and other substances as the water leaves the cell or passes through a membrane trying to restore equilibrium.