Pigments are important in the lives of all organisms, most especially plants. Pigments in the leaves of plants are called chlorophyll. There are different types of plant pigments:
• Anthocyanins—red chlorophyll
• Carotenoids—orange or yellow
• Green chlorophyll—the most common type of chlorophyll
Chlorophyll is a key ingredient in the process of photosynthesis. Through this experiment, you will be able to see the hidden pigments in a fresh green leaf and predict the color of the leaf in the fall.
What you need:
• Green leaves
• Filter paper, chromatography filters, or coffee filters
• Drinking glass or beaker
• Plastic wrap
• Isopropyl alcohol
How you make it:
Separate the different leaves from different sample trees.
Tear each leaf into different pieces. Place the pieces in beakers, one for each leaf. Pour alcohol into each beaker, just to cover the pieces completely.
With clear plastic wrap, cover each beaker to prevent the alcohol from evaporating.
Place each beaker in a dish filled with tap water. Give it about half an hour or until the isopropyl alcohol turns as green as the pigments in the leaf diffuse.
Cut out a strip of filter paper (1/2 of an inch) and then tape it to your pencil. Place the pencil on the beaker’s rim, suspending the strip above the beaker. Let the filter paper dip into the colored alcohol.
The colored alcohol will crawl slowly up to the filter paper. After about 30 to 90 minutes, the green coloration should disperse into various colors as the pigments part. Shades of different colors including green is a normal result on the filter paper. Take note which of the leaves have the greatest number of pigments. Based on your results, try to tell which leaves will be the most or least vibrant this autumn.