Innovators 7/ The Science of Fall or The reason why you collected leaves!

As the Earth orbits around the sun and turns on its axis, the seasons change.  When the seasons change, many organisms begin a cycle of preparation for the upcoming seasonal conditions.  One of the most common indicators of seasonal change is the leaves of trees.  When the days begin to shorten and the cooler temperatures set in, the deciduous trees of the temperate climates begin a beautiful transformation that eventually results in trees going into a state of winter dormancy. 

What actually happens to the leaves from a scientific perspective?  The laboratory exercise that you will conduct will allow you to extract the various pigments and compare their levels based on the colors of the leaves.  

All leaves contain the pigment chlorophyll, its what gives the leaves their green color.  All plants including trees undergoes the process of photosynthesis which allows the leaves to produce nutriebnts for the tree.  When autumn arrives, this process begins to slow and eventually stop.  this occurs for a variety of reasons, one being the loss of chlorophyll.  when chlorophyll begins to wane, the color of the leaf begins to change as well.  It will no longer take on the green appearance, it may become yellow (xanthophylls), red (anthocyanin), orange (carotene), brown (tannin) or even purple (anthocyanin)!  Who though the fall season was so full of science?