Glossary
Hypertonic Solution
A solution with a higher solute concentration compared to another solution, causing water to move out of the cell.
Example:
Eating too much salty popcorn without drinking water can make your blood plasma a hypertonic solution relative to your cells, drawing water out of them.
Hypotonic Solution
A solution with a lower solute concentration compared to another solution, causing water to move into the cell.
Example:
If you place a red blood cell in pure water, the water acts as a hypotonic solution, causing the cell to swell and potentially burst.
Isotonic Solution
A solution with the same solute concentration as another solution, resulting in no net movement of water.
Example:
Saline solution used in hospitals is an isotonic solution to human blood, preventing damage to red blood cells.
Osmosis
The net movement of water molecules across a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration.
Example:
The absorption of water by plant roots from the soil is a prime example of osmosis.
Semi-permeable membrane
A biological membrane that allows certain molecules or ions to pass through it by diffusion, but restricts the passage of others.
Example:
The cell membrane acts as a semi-permeable membrane, carefully regulating what enters and exits the cell.
Solute
A substance that is dissolved in a solvent to form a solution.
Example:
In a sugary drink, the sugar is the solute dissolved in water.
Tonicity
A measure of the effective osmotic pressure gradient, as defined by the water potential of two solutions separated by a semipermeable membrane.
Example:
Understanding the tonicity of an IV fluid is crucial to ensure it doesn't cause a patient's red blood cells to swell or shrink.