Here's a breakdown:
* Osmosis is the movement of water molecules across a semi-permeable membrane from a region of high water concentration to a region of low water concentration.
* Semi-permeable membranes are membranes that allow some substances to pass through while blocking others. Cell membranes are semi-permeable.
* Water concentration is determined by the concentration of solutes (dissolved substances) in a solution. The higher the solute concentration, the lower the water concentration.
How Osmosis Works:
1. Concentration Gradient: When there is a difference in water concentration across a semi-permeable membrane, water molecules move from the area of higher concentration (where there are fewer solutes) to the area of lower concentration (where there are more solutes). This movement is driven by the concentration gradient.
2. Equilibrium: Water movement continues until the concentration of water is equal on both sides of the membrane, or until a state of equilibrium is reached.
Example:
If a cell is placed in a solution with a lower solute concentration (hypotonic solution) than the inside of the cell, water will move into the cell. This is because the water concentration inside the cell is lower than the water concentration outside the cell.
Important Note:
Osmosis is a passive process, meaning it doesn't require the cell to expend energy. It occurs naturally due to the difference in water concentration and the semi-permeable nature of the cell membrane.
