Key elements of the definition:
* Solvent: The substance that dissolves the solute. In biological systems, this is usually water.
* Solute: The substance being dissolved in the solvent.
* Semipermeable membrane: A membrane that allows the passage of solvent molecules but not solute molecules.
* Concentration gradient: The difference in concentration of the solute between the two regions separated by the membrane.
* Equilibrium: A state where the concentration of the solute is equal on both sides of the membrane, and there is no net movement of solvent molecules.
In simpler terms:
Osmosis is the process of water moving across a membrane to try and balance out the concentration of dissolved substances (like salt) on either side of the membrane. Water moves from the area where there's less salt (and more water) to the area where there's more salt (and less water).
Example:
Imagine a glass of water with a semipermeable membrane separating it from a solution of salt water. Water will move from the glass of pure water into the salt water solution, because the concentration of water molecules is higher in the pure water. This movement will continue until the concentration of water molecules is the same on both sides of the membrane.
