IB 1108 L20 Photosynthesis

Describe how the functional units for beta carotene, xanthophyll, chlorophyll A, and chlorophyll B are different. Be sure to identify the subunits that adhere to paper during chromatography. Beta carotene are the yellow colors which transport light to chlorophyll, Xanthophyll are the yellow shades that are in the gathering of carotenoid. Chlorophyll appears to be more in the xanthophyll. Chlorophyll A is the green color in plant leaves which retain light. All plants have chlorophyll which helps the plant to deliver sustenance for the entire plant. Chlorophyll A utilizes oxygen. Chlorophyll B is yellow in shading. It is more soluble than chlorophyll An in light of the fact that it utilizes carbonyl shades as opposed to chlorophyll A which utilizes oxygen atoms. Describe a technique for measuring photosynthetic rate. You can measure photosynthetic rate via the production of oxygen. Oxygen can be measured by counting bubbles evolved from a water plant, or by using the Audus apparatus to measure the amount of gas evolved over a period of time. Many deciduous trees have leaves that turn yellow in the fall. What do you suppose is happening in the leaves at the cellular and molecular level? I suppose what is happening to the leaves at the cellular and molecular levels of the deciduous trees in which are turning yellow in the fall is due to the nights being longer and the days shorter. Typically in the fall it gets dark much earlier than the seasons of spring and summer. The chloroplasts contained in their cells as a result of all this are breaking down thus, not able to retain its pigment. If the leaves are not able to retain pigment, this is going to prevent the plant from performing photosynthesis. Chloroplasts and mitochondria are both unusual in that they have double membranes and contain their own set of DNA. Can you think of any explanations for this observation? Endosymbiotic Theory can explain this observation because it can be explained that the double membrane of both chloroplast and mitochondria are as a result of them being subjected to phagocytosis but they were not digested. Their DNA suggests that they were once free-living prokaryotes. This agrees with the endosymbiosis theory which states that eukaryotic cell organelles developed from prokaryotic cells. Experiment 1: Paper Chromatography Result Tables Table 1: Chromatography Data Solvent Distance from Original Line to Solvent Front Number of Bands Rf Factor Water 4.8 cm 1 (green) 0.041667 Acetone 5 cm 3 (green, yellow, orange) 0.86 Mineral Oil 0.4 cm 2 (green, yellow) 0.5 Acetic Acid 0 cm 1 (green) 0 Table 2: Photosynthesis Data Test Tube Are chloroplasts present? Initial Color Final Color Time Required to Change Color (Hours) 1 no Dark Blue Dark Blue/Purple 8 2 yes Dark Blue Black 9.5 3 yes Dark Blue Clearish yellow 12 Post-Lab Questions What did the different colored bands signify in each solvent for Part 1? What pigments can you associate them with? The many-colored bands in each solvent signify the different materials that are found within the Spinach. The green bands signify the chlorophyll found in the leaves and the yellow bands are carotenoids. What is the osmolarity fluid used in Part 2? Why is this important? Why is it essential to keep it cool? The fluid used in the experiment was Sucrose solution. This fluid is significant because it regulates the natural reaction of the leaves and also prevents interference from outside sources. It was essential to keep it cool because cold temperature helps inhibit the rate of photosynthesis so it gives protection to degradation of proteins. How could you modify this experiment to show the effects of different wavelengths of light on the photosynthetic rate? You could modify the experiment to show the effects of different wavelengths of light on the photosynthetic rate by adding more test tubes to the experiment. Some plants (grasses) tend to contain a greater concentration of chlorophyll than others (pines). Can you develop a hypothesis to explain this? Would it be testable? I think that grasses have a greater concentration of chlorophyll then pines because the lifespan of the grass is shorter. This hypothesis can be tested by comparing the amount of chlorophyll in grass and pine to their ages, with the results being recorded.