Osmosis: Water Movement Across Cell Membranes
Osmosis
Osmosis is the net movement of water molecules across a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration.
Water movement is crucial for cellular function, allowing cells to maintain their internal environment and balance solute concentrations.
Water Moves Because Of The Concentration Gradient
- Solutes (e.g., salts, sugars) bind with water molecules, reducing the number of free water molecules in the solution.
- A solution with higher solute concentration has fewer free water molecules.
- Water moves from where there are more free water molecules (lower solute concentration) to where there are fewer free water molecules (higher solute concentration).
- This creates a concentration gradient that drives osmosis.
- Think of water as someone who hates crowds.
- When stuck amongst a group of loud and annoying people, it'd naturally leave to somewhere quieter and less cramped.


