Learning Outcomes:
i. Students will define turgor pressure and describe its role in plants.
ii. They will understand the physiological processes influenced by turgor pressure.
Content:
i. Turgor: The Force Within: Turgor pressure is the force exerted by water inside the plant cell against the cell wall. When a plant cell absorbs water by osmosis, it swells, but the rigid cell wall prevents it from bursting. The resulting pressure is what we call turgor.
ii. The Role of Turgor in Plants
It maintains the structural integrity of the plant, keeping stems and leaves erect.
Turgor pressure is also essential for the growth of plant cells, which expand as they take up water.
It plays a role in the opening and closing of stomata, which are tiny openings on the leaves that allow for gas exchange.
In non-woody plants, especially, turgor pressure is crucial for overall support since these plants lack the rigid support structures found in woody plants.
List of Important Questions for Self-Study:
i. What is turgor pressure, and how is it generated in plant cells?
ii. Why is turgor pressure crucial for plant rigidity?
iii. How does turgor pressure affect the process of stomatal opening and closing?
iv. What might happen to a plant if it loses turgor pressure?
v. How do environmental conditions like water availability affect turgor pressure?
vi. Why is turgor pressure important for the growth of young plant cells?
vii. What is the relationship between turgor pressure and wilting in plants?
viii. How does turgor pressure contribute to the non-woody plant's ability to stand upright?
ix. Can turgor pressure influence how nutrients are transported within a plant?
x. How might a plant adapt its turgor pressure in response to changes in humidity?
Important Terminologies Used in Lesson:
Turgor Pressure: The pressure that water molecules exert against the cell wall.
Osmosis: The diffusion of water through a semipermeable membrane from a region of low solute concentration to a region of high solute concentration.
Stomata: Small openings on the underside of a leaf that allow gases and water vapor to pass in and out of the leaf.
Wilting: The loss of stiffness in non-woody parts of plants, which is typically a sign of water stress due to inadequate turgor pressure.
Cell Wall: The rigid layer lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants, it consists mainly of cellulose.
