When you were a kid, did you ever ask your parents "Why is the sky blue?" only to have them say "What other color would it be?"This fall, when your kids ask you about why the leaves on trees change color, you'll know.
Leaf color comes from pigments. Pigments are natural substances produced by leaf cells. The three pigments that color leaves are:
- chlorophyll (green)
- carotenoid (yellow, orange, and brown)
- anthocyanins (red)
Chlorophyll is the most important of the three. Without the chlorophyll in leaves, trees wouldn't be able to use sunlight to produce food.
Carotenoid create bright yellows and oranges in familiar fruits and vegetables. Corn, carrots, and bananas are just a few of the many plants colored by carotenoid.
Anthocyanins add the color red to plants, including cranberries, red apples, cherries, strawberries and others.
Chlorophyll and carotenoid are in leaf cells all the time during the growing season. But the chlorophyll covers the carotenoid -- that's why summer leaves are green, not yellow or orange. Most anthocyanins are produced only in autumn, and only under certain conditions. Not all trees can make anthocyanins.
Read on: The Wisconsin Department of Natural Resources has a great page (mainly geared towards kids).
No comments:
Post a Comment