The Action Spectrum and the Absorption Spectrum

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The Action Spectrum and the Absorption Spectrum Introduction: The purpose of this experiment is to learn the rates of photosynthesis under different lights, and the absorbance of photosynthetic pigments in spinach extract. “There would be no biology without photosynthesis. Plant biomass is the food and fuel for all animals. Plants are the primary producers. These amazing organisms are capable of capturing the energy of sunlight and fixing it in the form of potential chemical energy in organic compounds.” (Measuring the rate of photosynthesis) “Light is one of the main factors that affects the rate of photosynthesis, which literally means using light to create something new.” (What Are Three Factors That Affect the Rate Which Photosynthesis Occurs?) This experiment was to compare how the Elodea photosynthesized when absorbing different colors of light, and to measure the absorbance from 500 nm of wavelength to 750 nm. Based on three types of pigments that are present in plants: chlorophyll, carotenoids, and phycobilins, it was predicted that both of the rates of photosynthesis and the absorbance of different wavelengths were high under the colors of violet-blue or orange-red, while rates were low under the light color of green-yellow. Materials and Procedures: The materials used for this experiment were as follows: Elodea leaves (that have been kept in the dark), spinach leaves, blender, cheesecloth, spectrophotometer, cuvettes, beakers, large test tube, 5% sodium bicarbonate, Kimwipes, razor blade, tape, 100 mL graduated cylinder, graduated pipettes with rubber tubings, light source, ring stands and clamps, cellpphane paper. In activity 2a, green test tube was clamped to a ring stand, and filled three quarters to the top with 5% sodium bicarbonate. A 10 mL graduated pipette was held upside down and place a short piece of rubber tubing over the delivery end.

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