This preview shows page 1. Sign up to view the full content.
Unformatted text preview: Photosynthesis
2. a. Calculate the rate of DCPIP reduction (= rate of absorbance change) for methyl amine, DCMU, and the light control (use only the decreasing part of the curve for your calculations). Include units. i) RATE LIGHT ii) RATE METHYL AMINE iii) RATE DCMU b. What is the mechanism underlying DCMU? What is the mechanism underlying methyl amine? 3. What is the purpose of the dark control? What is the purpose of the light control? (What are you checking in both cases?) Explain. Worksheet continued on the backside. A23
4. Indicate your results for the chromatography. Chlorophyll a and Chlorophyll b Include the Rf values for all 3 carotenoid bands and for direction of solvent migration Label solvent front, pigment location, pigment name, color and identity. Include Rf values by each. pencil line How might the Rf values indicate chemical differences between Chlorophyll a and b, and the various caretenoids? 5. Calculate the rate of oxygen evolution (moles O2 evolved per minute) for the light control. To do this, choose the largest linear segment, but decreasing part of your graph and calculate the rate of change in absorbance. One mole of O2 is equivalent to 19,000 absorbance units. Show your work in the space provided 6. What results would you predict if both DCMU and Methylamine had been added at the same time? Explain. 7. How much NADP+ is being reduced, relative to the DCPIP, in the light under your conditions? Less, about the same, or more? Explain your answer. 8. What was the color of fluorescence of the UV irradiated acetone extracted chloroplast pigments? 9. Graph the absorption spectrum for your crude pigment extract (like fig. 4 on p. 123, your data is on p. 128). 10)
View Full Document