User:TIMOTHYtyriqcampbell/Lab report on the testing of starch in green leaves

Name: Tyriq Campbell 	Date:11\11\13	 Class: 1C Aim: This experiment was done on green leaves to determine if starch is present.

Materials/Supplies: Leaf, tripod-stand gauze Bunsen burner, beaker, boiling tube, ethanol, Petri-dish, iodine solution

Procedure: In this experiment a beaker of water was heated on tripod stand and gauze. A leaf was selected and dipped in the boiling water to kill and soften the leaf then the Bunsen burner was turned off. The boiling tube was then filled ¾of the way with alcohol and then the green leaf was pushed inside the boiling tube then the test tube was then immersed in the beaker of hot water for 10 minutes. The leaf was then taken out of the boiling tube and the ethanol washed off by dipping it in the water. The leaf was then placed in a Petri dish and an iodine solution added to the leaf to test for starch.

Result: After the leaf was boiled it became a pale looking color and it also became very soft. The color of the water in the beaker became green. This green colored water reacted to the alcohol and then it became discolored. Then when the iodine was added to the leaf it became a greenish blue black color.

Conclusion: The iodine was able to penetrate the surface area of the boiled leaf and reacts with starch which caused the colour that was seen. This now proves that starch is present in green leaves