Why Starch is Stored in Leaves:
* Photosynthesis: Leaves are the primary sites of photosynthesis. During this process, plants use sunlight, carbon dioxide, and water to produce glucose (sugar).
* Energy Storage: Excess glucose produced during photosynthesis is converted into starch, a more stable form of energy storage. Starch is stored in the chloroplasts of leaf cells.
The Purpose of Destarching:
* Experiments: Destarching is a crucial step in experiments designed to investigate photosynthesis. By removing the stored starch, researchers can isolate and observe the effects of specific variables (like light or carbon dioxide) on the production of fresh starch.
* Understanding Leaf Function: Destarching helps demonstrate how leaves function as the primary food-producing organs of plants.
How Destarching is Done:
1. Depriving the Leaf of Light: Plants are placed in a dark environment (usually overnight). This stops photosynthesis, preventing the production of new starch.
2. Using the Stored Starch: The plant is forced to use its stored starch for energy, as it's no longer producing new sugar.
Identifying a Destarched Leaf:
* Iodine Test: A solution of iodine is used to test for the presence of starch. Starch turns a dark blue-black color in the presence of iodine. A destarched leaf will not show this color change.
In Summary:
Destarching a leaf involves removing the stored starch from the leaf cells. This is achieved by depriving the leaf of light, forcing the plant to utilize its existing starch reserves. This process is essential for conducting experiments on photosynthesis and for better understanding the role of leaves in plant function.
