"Starch in plants" Return to list of pracs

Aim: This activity is used to measure the amount of starch in pot plant leaves.

Equipment: The equipment includes...  

Method: Place a pot plant in a dark closet for 2-3 days until the leaves start to turn a bit white. Take it out and masking tape black cardboard across a small section of 2-3 leaves. Leave the pot plant in the sunlight for 3-4 hours and then remove the black cardboard strips. Mix 5mL of iodine with 45mL of water and use this mixture to "paint" over the entire leaves to note the difference of the amount of starch formed within the covered strip or the uncovered strip...

Background knowledge: Starch forms with the aid of sunlight. The black cardboard strips cover the production of starch from the sunlight along that length of leaf.

Additional experiments: Add some of your iodine solution to examples of foods such as biscuit, cake, banana and bread to test for starch - if it turns black.