Question

To test starch in a leaf, why is it heated in alcohol first?
Give a brief answer..

Answer 1

Answer:

here is your answer; The hot water kills the leaf and the alcohol breaks down the chlorophyll, taking the green color out of the leaf.

Explanation:

When you put iodine on the leaves, one of them will turn blue-black and the other will be a reddish-brown. Iodine is an indicator that turns blue-black in the presence of starchThis procedure kills a leaf, disrupts the cell membranes and softens the cuticle and cell walls. This makes it possible to extract the chlorophyll with hot ethanol and also allows the iodine solution to penetrate the cells and react with any starchpresent.In your experiment, you took a leaf that had been allowed to do photosynthesis, youboiled it to kill it and remove the waxy cuticle, then placed it in alcohol to remove the chlorophyll and other plant pigments. Once the pigments have been removed, the leaf is treated with iodine solution.