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Photosynthesis Lab Background Plant pigment include green chlorophylls, orange carotenes, yellow xanthophylls, and red and blue anthocyanins. Plant pigments can be isolated by chromatography. The process of chromatography separates compounds from one another because of their different solubilities in water or other solvents. In paper chromatography, a piece of filter paper is used to separate and indicate the individual substances. The substances appear as colored bands or colored spots at different points on the filter paper. The filter paper and spots are called a chromatogram. Plant pigments function as absorbers of different wavelengths of light during photosynthesis.
. Green plants synthesize their own food from carbon dioxide and water. In the process of photosynthesis, green plants produce food in the form of carbohydrates. Another product of photosynthesis is oxygen. The energy for photosynthesis comes from the sun. Sunlight, a form of radiant energy, is absorbed by the pigments in the leaves of green plants. The radiant energy is converted into chemical energy can be used by the plants.
The sunlight needed for photosynthesis, as well as the light from artificial sources such as light bulbs, is white light. White light is composed of all the different colors of the visible light spectrum. By using a prism, a solid triangular piece of glass, white light can be separated into its many wavelengths. The wavelengths become visible as different colors. Not all wavelengths are absorbed and used by green plants for photosynthesis. Some wavelengths are reflected by the plant. For example, green light is reflected away pigment chlorophyll absorbs and, therefore, uses mostly red and blue light. Only the colors of light absorbed by a plant are used for photosynthesis.
This information is from the Prentice Hall Biology: The Living World Laboratory Manual made in 1989.
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