Experiment a. Effect of Wavelength on Photosynthetic EffectivenessHydrilla verticilata Objective: Seeing the effect of wavelength (colored paper) on photosynthetic activity Materials and tools: Plant material : : Two stalksHydrilla verticilata Chemical material : 0.5 % Na HCO3 Tools : Test tube, glass beaker, marker, pipette, 5 ml measuring cup, plastic transparent red, green, blue and yellow Ways of working: 1.Hydrilla verticilata One stalk is inserted into the tube with the shoot towards the bottom of the tube. 2. The tube is filled with 0.5% Na HCO3until it's full, then place it upside down in a glass beaker in such a way that no air space forms. 3. Bekker glass is wrapped in colored plastic and placed in the sun for 2-3 hours. 4. Beat the walls of the tube to release the bubbles from the plant. Stand the tube up and mark the air space that forms with a marker. 5. The contents of the tube are removed, then dried and filled with water using a pipette to the marked level. After that, the volume of water present is measured with a measuring cup. This volume of water is equal to the volume of oxygen formed during photosynthesis. Compare the effect of color on these reactions. Experiment b. Determination of Chlorophyll Levels Using a Spectrophotometer Objective: 1. Learn and give practice on how to use a spectrophotometer 2. Determination of chlorophyll levels in leaves Materials and tools: Plant material : Leaves of several types of plants in shaded and exposed conditions sunlight Chemical material : Acetone 80% Tools : : Spektronic 20 Bausch and Lomb, porcelain mortar, centrifuge, glass measuring 100 mL or 50 mL, cuvettes, aluminum foil, centrifuge tubes, ohaus scales and bottles. Ways of working: 1. Weigh 0.5 grams of fresh leaves. 2. The leaves are then chopped into small pieces and then extracted with 50 mL of 80% acetone by grinding in a mortar. Use acetone little by little so that it doesn't evaporate because this substance evaporates easily (be careful: acetone vapor causes dizziness and hallucinations). Grinding is carried out until all the chlorophyll is dissolved in 80% acetone with the characteristic that the dregs have turned white. 3. The extract was filtered using a Buchner filter and added to a 50 mL measuring cylinder. The addition of 80% acetone is only needed if the extract volume has not reached 50 mL after extraction. 4. Then the solution was centrifuged for 15 minutes at a speed of 2500 rpm. 5. Using a cuvette, the optical density (OD) of the extract was measured using Spectronik 20 Bausch and Lomb at wavelengths of 645 and 663 nm. 6. The chlorophyll content can be calculated by comparing the OD at wavelengths of 645 and 663 nm according to the equation: total chlorophyll = [20.2 (D645) + 8.02 (D663)] x (V/1000 x W) chlorophyll a = [12.7 (D663)– 2.69 (D645)] x (V/1000 x W) chlorophyll b = [22.9 (D645)– 4.68 (D663)] x (V/1000 x W) D = optical density read on a spectrophotometer V = volume of 80% acetone used to extract chlorophyll (ml) W = fresh weight of extracted plant tissue (g) mg total chlorophyll/g tissue = mg chlorophyll a/g tissue + mg chlorophyll b/g tissue Experiment c. Separation of Photosynthetic Pigments by Paper Chromatography Method Objective : to see the photosynthetic pigment components in the leaves and compare the molecular sizes of the components based on their movement during the chromatography process. Tools and materials Tool : a set of chromatography tools, knife, coins, 100 mL measuring cup Material : leaves, chromatographic solution mixed with petroleum ether and acetone (9 : 1) chromatography paper (whatmann paper), thread. Ways of working 1. Prepare filter paper measuring 2. Rub the surface of the leaf against the surface of the filter paper using a coin so that the leaf color pigment moves onto the filter paper 15 times to ensure the transfer of chlorophyll. 3. Place the filter paper on the chromatography tool which has been filled with chromatography solution, make sure that the part containing the color pigment from the leaf does not sink in the solution and close the mouth of the chromatography tool tightly so that the evaporation of the solution does not spread out. 4. Let the solution rise until it reaches the top of the paper (the solution moves about 15 cm). Then remove the filter paper and let it dry. 5. Observe the color that forms after the filter paper is completely dry. 6. Measure the RF of each color pigment produced with the equation Pigment mileage RF = solvent mileage 7. What can be concluded from this experiment.