What Causes Dcip to Lose It's Color?

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What Causes DCIP to Lose Its Color?
Chloe Gearhart
2.23.2012
Concepts Lab

Introduction:
Plants consume light for energy by converting carbon dioxide and water into glucose and oxygen, known as a process called photosynthesis. By adding hydrogen ions to carbon dioxide C-H bonds are made that hold energy which is released in mitochondrion, an organelle. This process of the release of energy is known as respiration. Without respiration, photosynthesis would not be able to perform. The process of photosynthesis is able to perform its duties with the help of an organelle called chloroplast as well. Within the chloroplasts lie thylakoids, a membrane system that contains pigments which are used to capture light energy. Photosynthesis is also responsible for reducing carbon dioxide into glucose, because reducing power is present. Reducing power is made after electrons get excited in the chlorophyll molecule. To carry out the process of reducing carbon dioxide into glucose, hydrogen ions must be added to the carbon of carbon dioxide where ATP and NADPH (reducing power) are used to convert carbon dioxide to sugar, all of which takes place in the chloroplast. The part of photosynthesis that converts carbon dioxide to sugar is known as Calvin Cycle of Dark reaction. For this lab, we will test the process of photosynthesis by using Spinach leaves to observe the Hill Reaction. The Hill Reaction tests water splitting in photosynthesis, and can be observed when a color change occurs. This color change will occur when a molecule is split and electrons are removed from molecular oxygen and hydrogen ions. DCIP combined with sucrose or ethanol spinach mixtures, will give either a green color (indicating photosynthesis occurred) or no color at all (indicating no photosynthesis occurred), depending on the factors and environments to which the mixtures will be tested. In experiment one, membrane integrity of the spinach was tested. If the DCIP was mixed with either the sucrose or ethanol and turned green it means the photosynthesis process worked, but if it stayed blue, photosynthesis was unable to perform. Knowing that sucrose is only a polar molecule because it dissolves in water, and polar molecules are hydrophilic, and ethanol can be both polar and nonpolar, I predict the solution with the sucrose will have a higher photosynthetic success. Sucrose is not hydrophobic; therefore the cells will stay intact rather than blowing up from excess water, making it easier for photosynthesis to work. In experiment two, temperature will be tested by placing one set of two test tubes (one with the ethanol and one with the sucrose solutions) in a cold water bath, and one set in room temperature. If the sucrose and ethanol test tubes were placed in an ice water bath and room temperature, then the test tubes with the solutions at room temperature will undergo the most photosynthesis because most photosynthetic processes occur at a temperature closer to room temperature than extreme cold conditions. The third experiment will test influence of the mixtures exposed to light versus no light on the photosynthetic success of sucrose and ethanol spinach leaf mixtures. If the sucrose and ethanol spinach mixtures are combined with DCIP solution, then the solutions exposed to no light will have a lighter/colorless product because the photosynthesis process functions better in light and the colorless solution proves the greater photosynthetic success. For the fourth experiment, influence of distance to light will be tested for photosynthetic success. Because photosynthesis works better with more exposure to light, the test tubes placed closer to the light will have a higher photosynthetic success.

Methods:
Experiment 1
We collected two test tubes and labeled them as: Ethanol and Sucrose. In the first test tube, Sucrose, we added 4mL of the DCIP solution, and then 4 drops of the ethanol spinach leaf extract. In the second tube,...
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