Please attach your Excel file here (or a PDF of an Excel type file). It should include 3 "sheets" in your workbook/spreadsheet, 1 for each portion of the lab:
Sheet 1: Effect of Light Intensity on the Rate of Photosynthesis
Sheet 2: Rfcalculations for Paper Chromotography
Sheet 3: Absorption Spectrum of Chloroplast Extract
Week 9 Photosynthesis202120 - BIOL-150-22720 Course Content Unit 3 - Weeks 9 - 12 Page 6 of 7 Absorption Spectrum of Chloroplast Extract 1. Based on your observations, which wavelength (color) of light might be expected to generate the lowest rate of photosynthesis? _________ An instrument called spectrophotometer can be used to pass light of specific wavelengths through a sample of chloroplast pigments dissolved in a solvent (you can review the module on spectrophotometers from earlier in the term). The degree of absorption of each of the wavelengths of light by the pigments can then be measured. The resultant data can be plotted on a graph, thus producing an absorption spectrum of the pigment mixture. Since all green plants don't have exactly the same type and amount of photosynthetic pigments, the spectra may vary from one species of plant to another. The pigment solution is prepared by mixing several plant leaves with acetone and then homogenizing them in a blender. Acetone is a nonpolar organic solvent in which the pigment molecules are soluble. This mixture is then filtered to remove all debris. The biology lab technician has already prepared the mixture for you. The solvent is extremely flammable, so use caution in handling both the pigment solution and the solvent. Record the absorbance for the specific wavelengths given in the Table 3. You should calibrate (blank) the spectrophotometer every time you change the wavelengths. Note this data is provided for you in Table 3. Table 3: Absorption Spectrum Data for Spinach Chloroplast Extract Wavelength Absorbance Wavelength Absorbance Wavelength Absorbance 380 nm 0.725 500 nm 0.139 620 nm 0.100 400 nm 0.834 520 nm 0.074 640 nm 0.135 420 nm 0.971 540 nm 0.047 660 nm 0.406 440 nm 0.844 560 nm 0.041 680 nm 0.049 460 nm 0.678 580 nm 0.059 700 nm 0.029 480 nm 0.338 600 nm 0.079 720 nm 0.000 Using Excel make a graph of the absorbance versus the wavelength. Underneath the graph in your Excel spreadsheet answer these two questions: My Blackboard Courses Community Page 6 of 7 Table of Contents Learning Objectives Background Information Photosynthesis Pre-lab Quiz Effect of Light Intensity on the Rate of Photosynthesis Separation of Chloroplast Pigments by Paper Chromotography Absorption Spectrum of Chloroplast Extract Photosynthesis Lab Henry Tolbert https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/courseMain?course_id=_90514_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1#contextMenu https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5567261_1&mode=reset https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5616386_1&mode=reset https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143534_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_1_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_2_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_3_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143534_1 https://bb-montgomerycollege.blackboard.com/webapps/login/?action=logout https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# 2. Based on your observations, which wavelength (color) of light might be expected to generate the highest rate of photosynthesis? _________ 3. Why are plants typically green? 4. Photosynthesis produces the oxygen (O ) on which all aerobic organisms depend for survival. What other factors make photosynthesis essential to the maintenance of virtually all life on earth? 2 absorption-spectrum-of-chloroplast-extract-202120-r1cmyda0.pdf Week 9 Photosynthesis202120 - BIOL-150-22720 Course Content Unit 3 - Weeks 9 - 12 Page 6 of 7 Absorption Spectrum of Chloroplast Extract 1. Based on your observations, which wavelength (color) of light might be expected to generate the lowest rate of photosynthesis? _________ An instrument called spectrophotometer can be used to pass light of specific wavelengths through a sample of chloroplast pigments dissolved in a solvent (you can review the module on spectrophotometers from earlier in the term). The degree of absorption of each of the wavelengths of light by the pigments can then be measured. The resultant data can be plotted on a graph, thus producing an absorption spectrum of the pigment mixture. Since all green plants don't have exactly the same type and amount of photosynthetic pigments, the spectra may vary from one species of plant to another. The pigment solution is prepared by mixing several plant leaves with acetone and then homogenizing them in a blender. Acetone is a nonpolar organic solvent in which the pigment molecules are soluble. This mixture is then filtered to remove all debris. The biology lab technician has already prepared the mixture for you. The solvent is extremely flammable, so use caution in handling both the pigment solution and the solvent. Record the absorbance for the specific wavelengths given in the Table 3. You should calibrate (blank) the spectrophotometer every time you change the wavelengths. Note this data is provided for you in Table 3. Table 3: Absorption Spectrum Data for Spinach Chloroplast Extract Wavelength Absorbance Wavelength Absorbance Wavelength Absorbance 380 nm 0.725 500 nm 0.139 620 nm 0.100 400 nm 0.834 520 nm 0.074 640 nm 0.135 420 nm 0.971 540 nm 0.047 660 nm 0.406 440 nm 0.844 560 nm 0.041 680 nm 0.049 460 nm 0.678 580 nm 0.059 700 nm 0.029 480 nm 0.338 600 nm 0.079 720 nm 0.000 Using Excel make a graph of the absorbance versus the wavelength. Underneath the graph in your Excel spreadsheet answer these two questions: My Blackboard Courses Community Page 6 of 7 Table of Contents Learning Objectives Background Information Photosynthesis Pre-lab Quiz Effect of Light Intensity on the Rate of Photosynthesis Separation of Chloroplast Pigments by Paper Chromotography Absorption Spectrum of Chloroplast Extract Photosynthesis Lab Henry Tolbert https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/courseMain?course_id=_90514_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1#contextMenu https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5567261_1&mode=reset https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5616386_1&mode=reset https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143534_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_1_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_2_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_3_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143534_1 https://bb-montgomerycollege.blackboard.com/webapps/login/?action=logout https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1# 2. Based on your observations, which wavelength (color) of light might be expected to generate the highest rate of photosynthesis? _________ 3. Why are plants typically green? 4. Photosynthesis produces the oxygen (O ) on which all aerobic organisms depend for survival. What other factors make photosynthesis essential to the maintenance of virtually all life on earth? 2 separation-of-chloroplast-pigments-by-paper-chromotography-22ulcswk.pdf Week 9 Photosynthesis202120 - BIOL-150-22720 Course Content Unit 3 - Weeks 9 - 12 Page 5 of 7 Separation of Chloroplast Pigments by Paper Chromotography 1. molecular weight 2. solubility in the specific solvent 3. affinity for the paper As was noted earlier, the primary photosynthetic pigment is chlorophyll a; however, other accessory pigments (e.g., xanthophylls and carotenes) are also typically present in the chloroplast, albeit in smaller quantities. There are several techniques by which these primary and accessory pigments can be separated. In this exercise, the separation will be accomplished by paper chromatography. When a solution of these pigments is placed on a strip of filter paper, the pigment molecules adsorb onto the cellulose fibers of the paper. When the tip of the strip of paper is then immersed into a suitable solvent, the solvent is absorbed by the paper and moves up the paper by capillary action. As the solvent passes the spot on which the pigment solution was placed, the pigments are dissolved by the moving solvent. The pigment molecules are generally unable to move as fast as the solvent, but some of them move faster than others. The differential movement of the pigments is caused by three main factors that differ among the pigments: Faster movement is associated with low molecular weight, high solubility in the solvent, and low affinity for the paper. The distance traveled by a particular pigment relative to the distance traveled by the solvent is specific for any given pigment and set of conditions. This relationship is called the R , and is calculated as follows:f The R for any given substance is constant in a specific solvent separation system; thus, it can be used to characterize the pigment molecules. f Experimental Procedure for completing the wet-lab. Please read so that you understand at what steps the data was collected and what the data represent. Table 2: Photosynthetic Pigments Separated by Paper Chromatography My Blackboard Courses Community Page 5 of 7 Table of Contents Learning Objectives Background Information Photosynthesis Pre-lab Quiz Effect of Light Intensity on the Rate of Photosynthesis Separation of Chloroplast Pigments by Paper Chromotography Absorption Spectrum of Chloroplast Extract Photosynthesis Lab Henry Tolbert https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/courseMain?course_id=_90514_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1#contextMenu https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5567261_1&mode=reset https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5616386_1&mode=reset https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143529_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1 https://bb-montgomerycollege.blackboard.com/bbcswebdav/pid-6143530-dt-content-rid-89835275_1/xid-89835275_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_1_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_2_1 https://bb-montgomerycollege.blackboard.com/webapps/portal/execute/tabs/tabAction?tab_tab_group_id=_3_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143529_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143531_1 https://bb-montgomerycollege.blackboard.com/webapps/login/?action=logout https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143530_1# Substance that migrated Distance from the origin Rf petroleum ether-acetone solvent 10.0 cm photosynthetic pigment carotenes 9.3 cm xanthophylls 4.3 cm chlorophyll a 5.3 cm chlorophyll b 1.3 cm Put the above data and calculations for the Rf on its own page of your Excel spreadsheet and then answer the following questions. 1. What can be deduced about a molecule that has a very high Rf? 2. Which pigment in spinach leaves do you think is most soluble in the petroleum ether-acetone solvent we used in today’s lab? 3. What is the maximum value that the Rf can be for any molecule? 4. Would you expect the Rf of chlorophyll a to be the same or different if the solvent were something other than that used in this exercise? Explain why or why not. effect-of-light-intensity-on-the-rate-of-photosynthesis-ndash-ebekhy44.pdf Week 9 Photosynthesis202120 - BIOL-150-22720 Course Content Unit 3 - Weeks 9 - 12 Page 4 of 7 Effect of Light Intensity on the Rate of Photosynthesis One of the products of photosynthesis is molecular oxygen (O ). Oxygen is only slightly soluble in water, so in a saturated solution, the excess oxygen will form gaseous bubbles. The rate of oxygen evolution by a plant immersed in water can be a reasonable measure of the rate of photosynthesis. We will set up a system that can measure the amount of oxygen gas released from plant leaves. We will use the system to determine the effect of varying light intensity (using light bulbs of differing wattage) on the rate of photosynthesis. 2 My Blackboard Courses Community Page 4 of 7 Table of Contents Learning Objectives Background Information Photosynthesis Pre-lab Quiz Effect of Light Intensity on the Rate of Photosynthesis Separation of Chloroplast Pigments by Paper Chromotography Absorption Spectrum of Chloroplast Extract Photosynthesis Lab Henry Tolbert https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/courseMain?course_id=_90514_1 https://bb-montgomerycollege.blackboard.com/webapps/blackboard/execute/displayLearningUnit?course_id=_90514_1&content_id=_6143529_1#contextMenu https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5567261_1&mode=reset https://bb-montgomerycollege.blackboard.com/webapps/blackboard/content/listContent.jsp?course_id=_90514_1&content_id=_5616386_1&mode=reset https://bb-montgomerycollege.blackboard