Question

Account for the following:

Wilted lettuce leaves become crisp/firm when placed in cold water for a while.

Answer 1

Effect of cold water on wilted lettuce leaves:

1. The cell sap of the wilted lettuce leaves has a higher concentration of solute and acts as a hypertonic solution.
2. When the wilted leaves are placed in cold water then, it acts as a hypotonic solution.
3. This leads to the inward diffusion of water molecules into the lettuce leaves.
4. The leaves will become turgid and crisp due to the process of endosmosis.