Hypertonic vs Hypotonic

Rarely do you come across entirely pure materials in your daily existence. Their significance and usage depend on their composition. A solution includes two components: solute and solvent. A solution is a homogeneous combination, where each particle exists as ions or single molecules. On the other hand, the size of the solute varies depending on the solution. A homogeneous mixture means that all the properties of this mixture are consistent. 

This article will elaborate on what hypertonic and hypotonic are and how to remember hypertonic vs hypotonic differences.

What is a Hypotonic Solution?

A solution with a lesser amount of solute compared to another solution is called a hypotonic solution. A cell placed in a hypotonic solution contains a higher concentration of solutes than the surrounding hypotonic solution. Pure water is also an example of a hypotonic solution. When a red blood cell is placed in a hypotonic solution, water enters the cell by osmosis because the red blood cell does not have a cell wall. As water enters, it creates osmotic pressure, which can cause the red blood cells to swell and eventually burst (hemolysis). This is why pouring water on a bloodstain can spread the stain further, as the red blood cells burst and release their contents.

If the cytosol of a cell contains more solutes than the surrounding solution, the external solution is called a hypotonic solution. When a plant cell is placed in a hypotonic solution, water enters the central vacuole, causing it to expand. The cell membrane pushes against the rigid cell wall, creating turgor pressure. The cell wall prevents the plant cell from bursting by providing structural support and resistance.

If confused as to when to give hypertonic vs hypotonic solutions, refer to the examples of hypotonic solution  uses given below:

• In hospitals, hypotonic solutions are used to treat dehydration in patients.
• Distilled water as compared to cell
• Saline solutions used in medicines have a nominal amount of solute compared to our blood, which is 0.45%, 0.25% saline and 2.5% dextrose solution.
• Drinks are prepared using small amounts of carbohydrates, around 6% solution.

What is a Hypertonic Solution?

A hypotonic solution has a lower solute concentration and a higher solvent concentration than another solution. When a cell’s cytosol is hypertonic, it means that the cytosol has a higher solute concentration than the surrounding environment, making the surrounding environment hypotonic. Solvent and solute flow according to their concentration gradients, typically with water moving from areas of lower solute concentration (hypotonic) to areas of higher solute concentration (hypertonic). Saltwater is an example of a hypertonic solution.

When a cell is placed in a hypertonic solution, osmosis causes water to move out of the cell to balance the solute concentrations on both sides of the cell membrane. In plant cells, the vacuole typically contains a hypertonic solution, which helps draw water into the cell, increasing turgor pressure and keeping the plant cell rigid.

Hypertonic solutions can affect nerve cells in animal cells. The ions in hypertonic solutions generate action potentials, which are crucial for nerve signal transmission. 

For those in doubt regarding when to use hypotonic vs hypertonic solutions, explore some of the examples of hypertonic solution uses discussed below:

• Sugary drinks are an example of hypertonic solution because they contain a higher volume of sugar as compared to water
• Hypertonic solutions are used in hospital IV drips and injections.
• Patients are given hypertonic solution with edema, and it is also used to replace electrolytes.
• Patients undergoing traumatic brain injury are treated with 23% or 7% hypertonic saline.
• Babies having a higher risk of hypoglycemia are treated with water with 10% dextrose.

How to Remember Hypertonic Vs. Hypotonic?

Refer to the table given below to learn the key points of Hypertonic vs Hypotonic:

Factors	Hypotonic solution	Hypertonic solution
Definition	When the solute concentration outside the cell is less than that inside the cell, the solution is hypotonic to the cell.	When the solute concentration is greater as compared to the inside of the cell, the solution is hypertonic to the cell.
Flow of water	Cell gains volume and swells	The cell loses volume and shrinks
Plant cell	Plant cells become turgid in a hypotonic solution	Plant cell undergoes plasmolysis when put in a hypertonic solution
Concentration level	Low concentration	High concentration
Expandability	Hypotonic solution swells up the cell	Hypertonic solution shrinks the cell
Food preservation	Used for food preservation	Not used for food preservation
Osmosis Affect	Cell acquire water by osmosis	Cell sacrifice water by osmosis

Conclusion

A hypotonic solution encompasses any element with more water and limited solute as compared to the cells. However, a hypertonic solution encompasses any element with more molecules or electrolytes than water or solvent. Both solutions have their own specific qualities and play a crucial role in the living systems of animals and plants. To learn more about hypotonic and hypertonic solutions, connect with the experts on the Turito online learning platform.

FAQs