Turgor Pressure

Definition

Turgor pressure is the pressure exerted by the fluid (usually water) inside the central vacuole of plant cells against the cell wall. This pressure is crucial for maintaining the structural integrity and rigidity of plant cells, allowing them to stay upright and support the overall structure of the plant. Turgor pressure plays a vital role in osmosis, where water moves into cells, increasing their volume and thereby exerting pressure on the cell wall.

5 Must Know Facts For Your Next Test

1. Turgor pressure is essential for plants to maintain their shape and prevent wilting; without it, plants can droop.
2. It is created when water enters the vacuole via osmosis, causing it to swell and push against the rigid cell wall.
3. High turgor pressure indicates that a plant cell is in a hypotonic environment, where there is more water outside the cell than inside.
4. In contrast, when a plant cell is in a hypertonic solution, turgor pressure decreases, leading to plasmolysis.
5. Turgor pressure not only helps in maintaining the plant's structure but also aids in processes like nutrient transport and growth.

Review Questions

• How does turgor pressure relate to the process of osmosis in plant cells?
  • Turgor pressure directly results from osmosis in plant cells. When a plant cell is placed in a hypotonic solution, water enters the cell through osmosis, filling the central vacuole. This influx of water increases the internal volume, creating pressure against the rigid cell wall, known as turgor pressure. This pressure is crucial for keeping the plant cells firm and maintaining overall plant structure.
• Discuss how turgor pressure influences the health and growth of plants.
  • Turgor pressure is fundamental for plant health because it helps maintain cell shape and prevents wilting. A sufficient level of turgor pressure allows plants to stand upright and supports their leaves for optimal sunlight absorption. Moreover, during growth, turgor pressure plays a role in expanding cells, which contributes to overall plant development and enables proper nutrient transport throughout the plant.
• Evaluate the implications of turgor pressure changes during drought conditions on plant survival and adaptation strategies.
  • Changes in turgor pressure during drought conditions can have severe implications for plant survival. As water becomes scarce, plants experience reduced turgor pressure, leading to wilting and potentially permanent damage if prolonged. To adapt, some plants develop strategies such as closing stomata to minimize water loss or accumulating solutes to retain water within their cells. These adaptations help them maintain some degree of turgor pressure and survive challenging environmental conditions.

Related terms

Osmosis:

The movement of water molecules across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Plasmolysis: The process in which cells lose water in a hypertonic solution, leading to the shrinking of the cell membrane away from the cell wall.

Cell Wall: A rigid layer surrounding the cell membrane in plant cells, providing structural support and protection.