10/18/2013 11:44:00 AM 'Naturally curious' Chisago Lakes middle
schoolers enjoy organic tie-dye biology class
Seventh grade students at Chisago Lakes Middle School are grinding up plants to extract pigments to use to Tie Dye t-shirts. Using mortar and pestle sets, they are pulverizing the local flora in search of the Anthocyanins, Xanthophylls, Chlorophylls, Tannins and Carotenes that give the Chisago Lakes area its beautiful fall colors.
The activity is part of the Nature Notebook unit in which students learn about the plants and animals of their backyard, the creatures they walk by every day, barely noticing. The learning target for this activity is to learn why leaves change color and to learn the names and importance of the plant pigments, while having fun in the name of science. Seventh graders also make the connection between the fall color and a diminishing amount of sunlight by taking note of daily sunrise and sunset readings.
Students were asked to explore their yards and cupboards for foods and plants that contain the various pigments. Students have brought in Sumac leaves, raspberries and wild grapes that are loaded with anthocyanin. One student brought in a bag full of grass clippings to mash and extract chlorophyll, while another student raided the pantry for Cilantro. (This helps the room smell a bit better by the way) Marigold flower petals, pumpkins, and squash yield Carotenes. Green Ash leaves and Sugar Maples among others produce the yellow xanthophyll pigments. Tannins, the brown pigment, can be obtained from a wide variety of plants including Bur oak.
“The seventh graders are naturally curious which makes them good scientists,” says instructor Pat Collins. “This messy lab helps to preserve and nurture that curiosity rather than beat it out of them with the memorization of facts. They find that plant pigments are everywhere, have great importance to our diets and are vital to the process of photosynthesis which is all important to life on earth.”