1. Osmosis:
* Water moves from high concentration to low concentration. This means water moves from the outside environment, where it's more concentrated, into the plant cell, where it's less concentrated.
* The cell wall is permeable to water. Water can easily pass through the cell wall.
* The cell membrane is selectively permeable. It allows water to pass through but regulates the movement of other substances.
2. Turgor Pressure:
* Water enters the vacuole. The vacuole is a large, fluid-filled sac within the plant cell.
* The vacuole expands. As water fills the vacuole, it pushes against the cell wall.
* Turgor pressure increases. This is the pressure exerted by the vacuole on the cell wall.
3. Cell Shape:
* The cell becomes turgid. Turgor pressure helps maintain the plant cell's shape and rigidity. This is crucial for plants to stand upright and for their leaves to be stiff.
4. Importance of Turgor Pressure:
* Plant support: Turgor pressure is the primary mechanism for maintaining plant structure.
* Leaf expansion: It allows leaves to unfold and capture sunlight for photosynthesis.
* Nutrient transport: It helps move nutrients within the plant.
* Wilting: When a plant loses water, turgor pressure decreases, causing the plant to wilt.
In summary, when a plant cell takes in water, the water moves into the vacuole, increasing turgor pressure and causing the cell to become turgid. This turgor pressure is essential for the plant's shape, support, and overall function.
