Essay about Photosynthesis Formal Lab Report

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Pages: 12


The purpose of this lab is to determine which pigments in a plant support or effect photosynthesis, based on starch production, which wavelengths of light are involved in photosynthesis, and identify plant pigments found in a plant leaf by means of paper chromatography. Life on Earth is dependent entirely on the energy from the Sun, not only to keep the planet at a suitable temperature but also to provide the energy required to sustain life. The energy of the Sun, in the form of photons, is actively captured by chlorophyll and related pigments present in photosynthetic organisms, like plants and algae. This captured energy is used to convert carbon dioxide into complex energy-rich molecules that can be used by themselves
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The water was brought to a slow boil and the leaf was placed into the boiling alcohol solution in order to extract the pigments. When the leaf became almost white, the leaf was removed, placed into a petri dish, and covered with distilled water. I2KI solution was added to the distilled water until a pale amber colour was obtained. The leaf produced a purple-black colour in some areas which show a positive test for starch. In the second part of the lab, part of a leaf was taken from a germanium plant that had been covered for several days with different colour filters: blue, green, red, and black. In order to differentiate between the leaves taken from different filters, the black filter leaf had one notch taken from leaf, the green had 2 notches, the red had 3 notches, and the blue had 4 notches. The leaves were then place into the alcohol bath that was used in the first experiment. When the leaves became mostly white, they were removed using forceps, placed into a petri dish, and rinsed and covered with distilled water. I2KI was added to the distilled water until an amber colour was achieved. The observation of the reaction of the leaves with the I2KI after 5 minutes was then recorded. See appendix for original lab report.

Lab 13 In this laboratory experiment, pieces of spinach leaves were mashed in a mortar and pestle in order to extract the plant’s pigments. These pigments were transferred to a