Will Godfrey
Chemistry
Miss. Morrison
May 21, 2000
Natural Indicators
Each year millions of tourists travel to the woods of New England, upstate New York, Wisconsin, and Canada to witness the appearance of brilliant autumn colors. Sugar maples, red oaks, sumac, birch and other trees and shrubs turn from green to bright red, orange, and yellow. The short, cool days of autumn bring an end to the production of chlorophyll (the green light-gathering pigment). As chlorophyll gradually breaks down, the colors of the more stable carotenoid (yellow/orange) and anthocyanin (red/blue/purple) pigments become visible. Some years the leaves of a particular species are bright yellow, while other years they may appear redder or even purple. Although no one can accurately predict the timing or coloration of each year's show, we do know that there is a chemical basis for it.
Anthocyanins (Figure I) are responsible not only for the red and purplish colors of autumn, but also for similar......
Join Now or Login to view the rest of this paper.
Approximate Word Count: 911
Approximate Pages: 4 (260 words per double-spaced page) |