Consider how lettuce or spinach placed in water becomes firm and crisp. Use what you have learned about cell membranes to explain this observation.

The cell membranes of the plants and other organisms are semi - permeable. This means that they allow other substances to get in and out while ban others. In this item, placing lettuce or spinach in water, allow water to get into the cell through the process called pinocytosis or "cell drinking". This process makes the leaves crispy.