Plant Pigments and Photosynthesis Lab Report

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Plant Pigments and Photosynthesis Introduction: Using chromatography, we will be separating plant pigments, as well as measuring the rate of photosynthesis in isolated chloroplast using the dye DPIP. Paper chromatography is a technique in which the solvent moves up the paper by capillary action, this is caused by the attraction of solvent molecules to the paper as well as the attraction of solvent molecules to one another. Because of capillary action the solvent moves up the paper causing the pigments to become visible at certain distances. Chlorophyll a is a main pigment that makes up about 75% of the pigmentation in plants meanwhile the other 25% is made up of Chlorophyll b. Carotenes and xanthophyll’s serve as accessory pigments that make up the rest of the pigmentation. Carotene is carried along near the solvent front because it is very soluble in the solvent being used and because it forms no hydrogen bonds with cellulose. Xanthophyll differs from carotene in that it contains oxygen. It is also found further from the solvent front because it is less soluble in the solvent and has been slowed down by hydrogen bonding to the cellulose. Chlorophylls contain oxygen and nitrogen and are bound more tightly to the paper than are the other pigments. The primary photosynthetic pigment in plants is Chlorophyll a. Chlorophyll a molecules as well as chlorophyll b and the carotenoids capture light energy and transfer it to the single chlorophyll a molecule at the reaction center. The carotenoids are carotenes and xanthophylls, which will protect the photosynthetic system from the damaging effects of ultraviolet light. Hypothesis: The rate of photosynthesis in plant cells is mainly determined by the amount of light it receives and the temperature around it. The cuvette containing unboiled chloroplasts that have been exposed to light will have an increasingly
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