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| Shared Idea |
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| Carotene
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| In the spring, many leaves show a red color before the more familiar green is seen. A variety of pigments are present in plants, and each plays an important role. Chlorophyll, which appears as green, is the main factor in capturing the sun’s energy in photosynthesis. However, the red we often see in spring and fall is due to the presence of another pigment, carotene.
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| Like chlorophyll, carotenoids play an important role in many photosynthetic organs. In addition, carotenoids play a part in many other roles. They are photo-protectors, helping prevent damage when the sunlight is too bright. Similarly, they also play a protective role as antioxidants. These chemicals serve as are precursors of plant hormones in other roles in plants. Carotene is also a color attractant for pollination by various animals.
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| Carotene is derived from the Latin name for carrots. Carotene gives the rich color to many yellow and orange fruits and vegetables. Over 8000 international units of vitamin A are present in one small carrot. This includes over 4000 micrograms of beta-carotene. While vitamin A is critical for good vision, it is fat soluble. This means that eating excessive amounts can eventually cause vitamin A to accumulate in the body, leading to hypervitaminosis and giving one’s skin an orangey color.
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| Xanthophyll is a similar chemical. However, unlike carotene, xanthophyll includes oxygen atoms in the molecules. Both carotene and xanthophyll are very visible in autumn in temperate regions. Plants withdraw chlorophyll from their leaves, preserving it for the coming year. These other pigments had always been present in the leaves, but they had been masked by the chlorophyll. They now become visible, accounting for the fabulous fall colors!
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