Osmosis is the movement of water molecules from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration) through a semipermeable membrane. This movement aims to equalize the solute concentrations on either side of the membrane.
Key points about osmosis:
Semipermeable membrane:
This is a barrier that allows water molecules to pass through but restricts the movement of other molecules (like solutes).
Solute and solvent:
Solutes are substances dissolved in a solvent (like water).
Movement from high to low:
Water moves from a region with a higher concentration of water molecules (less solute) to a region with a lower concentration of water molecules (more solute).
Equalizing solute concentrations:
Osmosis continues until the concentration of solutes is roughly equal on both sides of the membrane.
Biological importance:
Osmosis is crucial for many biological processes, including the movement of water into and out of cells, and the absorption of nutrients by plants.
Passive transport:
Osmosis doesn’t require the cell to expend energy to move water across the membrane.
Exosmosis and endosmosis:
These refer to osmosis where water moves out or into the cell, respectively.