What is Osmosis? Definition, Meaning & Example
The movement of water molecules across a semipermeable membrane from an area of higher water concentration to lower water concentration.
TL;DR: The movement of water molecules across a semipermeable membrane from an area of higher water concentration to lower water concentration.
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Osmosis: The movement of water molecules across a semipermeable membrane from an area of higher water concentration to lower water concentration.
Explanation
Osmosis is a special type of diffusion involving water molecules and a semipermeable membrane. Water molecules move to balance the concentration of dissolved solutes on both sides of the membrane. This process is crucial for plant cells to maintain turgor pressure and for animal cells to regulate water balance. In Indian schools, osmosis is taught as a key concept for understanding how cells absorb water and nutrients.
Example
When a plant cell is placed in pure water, water molecules move into the cell by osmosis because the cell sap is more concentrated than external water. The cell becomes firm and turgid.
Frequently Asked Questions
What is the difference between osmosis and diffusion?
Diffusion is the movement of any molecules, but osmosis is the specific movement of water across a semipermeable membrane.
Why do plant cells not burst in pure water like animal cells do?
Plant cells have a rigid cell wall that prevents excessive water intake and maintains the cell shape, whereas animal cells lack this wall.
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