Starch test Experiment

If starch is found in a leaf, it means phtotsynthesis has taken place. The question is: how to test a leaf for stach?
1. Pluck a leaf from a plant that has been exposed to sunlight for a few hours.
2. The leaf is then placed in a beaker of boiling water to kill and soften it.
3. The leaf is then removed from the boiling water using a celan glass rod.
4. It is subsequently put into a test tube containing some alcohol. Alcohol can decolourise the leaf by removing chlorophyll from it.
5. The test tube with the leaf inside is then placed very carefully into a beaker of hot water for the decolourisation process to take place.
If photsynthesis has taken place, glucose will be formed. Excess glucose produced is stored in the form of starch. The presence of starch in leaves shows that photosynthesis has taken place. The iodine test will be usd to test for starch. Iodine solution is yellowish brown in colour. Iodine solution turns blue-black in the presence of starch.