what happens to a leaf boiled in ethanol when iodine solution is added to it
When a leaf is boiled in ethanol, it removes the green pigment called chlorophyll, leaving behind a decolorized leaf. When iodine solution is added to the decolorized leaf, it reacts with the starch present in the leaf, resulting in a color change. The iodine solution turns blue-black in the presence of starch.
This reaction occurs because plants produce starch as a storage form of glucose, which is produced during photosynthesis. The presence of starch in the leaf indicates that photosynthesis has taken place. When the leaf is boiled in ethanol, it removes the chlorophyll, but the starch remains.
When iodine solution is added to the decolorized leaf, it forms a complex with the starch molecules, resulting in the characteristic blue-black color. This reaction is commonly used as a test for the presence of starch in plant tissues.
So, when a leaf boiled in ethanol is treated with iodine solution, the decolorized leaf will turn blue-black if starch is present, indicating the occurrence of photosynthesis in the leaf.