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Name: barnas
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Question:
How is chlorophyll released from the chloroplasts? Why is chlorophyll green? Why do leaves on trees change color?



Replies:
I'm not sure that I understand your first question. Chlorophyll is produced within the chloroplast and stays in the chloroplasts to function in collecting light energy for the plant to use for growth. Chlorophyll is a pigment, which means it absorbs visible light. Because of its particular molecular structure, it absorbs mostly red and blue light. Therefore, if you shine white light (which contains all of the colors), red and blue light will be absorbed and the other colors will be transmitted or reflected. The colors that are left over are perceived by the human eye as green. Leaves on trees change colors as pigments (including chlorophyll) begin to break down. Leaves typically contain chlorophyll, anthocyanins (red and blue), and carotenoid pigments (yellow and orange). As chlorophyll breaks down, the leaf color will reflect the pigments that are still present in the leaf.

-Brian



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