turgorivoimaan

Turgorivoimaan, often simply referred to as turgor pressure, is a fundamental concept in plant biology and certain microbial organisms. It describes the force exerted by the contents of a plant cell against its cell wall. This pressure arises from the influx of water into the vacuole, the large, fluid-filled sac within the plant cell. As water enters the vacuole through osmosis, it pushes the cytoplasm and the plasma membrane outwards, creating pressure on the rigid cell wall.

The cell wall, while providing structural support, also resists this outward pressure. The balance between the inward osmotic potential (the tendency of water to enter the vacuole) and the outward turgor pressure is what maintains the turgidity of plant cells. This turgor is crucial for various plant functions. It provides mechanical support to non-woody plant tissues, allowing them to stand upright and hold their leaves towards sunlight. Wilting in plants occurs when they lose turgor pressure due to insufficient water.

Furthermore, turgor plays a role in cell expansion and growth. As a cell grows, the cell wall must yield to the increasing turgor pressure, allowing the cell to enlarge. Turgor is also involved in phenomena such as the opening and closing of stomata, the pores on plant leaves that regulate gas exchange, and the movement of plant parts in response to touch, like the Venus flytrap. In some single-celled organisms, turgor pressure can also be important for maintaining cell shape and aiding in movement.