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19. Investigation of the effects of environmental factors on the rate of photosynthesis
The rate of photosynthesis of a photosynthetic plant is affected by factors such as light quality, light intensity, carbon dioxide concentration and temperature. A convenient way of investigating the effects of these factors on the rate of photosynthesis is to measure the volume of oxygen given off by a plant in a given time. When a particular factor is being investigated, it is essential that other factors are kept constant and, if possible, at optimum levels so that no other factors are limiting. Pondweeds, like Hydrilla and Ceratophyllum, are suitable plant materials for this investigation. It is advisable to use plant materials that have been well illuminated for three or four hours before the experiment.
Fig.1 Experimental set up
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A. To investigate the effect of light quality on the rate of photosynthesis Procedure 1. 2. 3. 4. 5. Cut the stem of a well-illuminated piece of Hydrilla to about 10 cm long. Place it with cut surface upwards, in a boiling tube filled with 0.25% sodium hydrogencarbonate solution. Wrap the tube with red cellophane. Set up the apparatus as shown in Fig.1. Stand the tube in a beaker of water at room temperature. Record the temperature of the water, which acts as a heat shield, and check it at intervals throughout the experiment. It should remain constant and the water should be renewed if necessary. 6. 7. 8. Put a 100-watt table lamp at 20 cm from Hydrilla. Turn on the lamp. Wait for about 5 minutes for Hydrilla to equilibrate. Suck the sodium hydrogencarbonate solution from the tube into the pipette. Close the clip and record the initial reading. Make sure that the clip is tightened to prevent the solution in the pipette from falling. 9. After a fixed period of time (e.g. 5 minutes), record the final reading in the pipette and calculate the volume of gas collected. 10. Repeat steps (2) to (9) using transparent and green cellophane respectively.
The Term Paper on Investigation Into The Factors Affecting Rate Of Photosynthesis
AIM- To identify the factors affecting the rate of photosynthesis and, choosing one factor, to ascertain the effects it has. Photosynthesis is an endothermic reaction that occurs in plants, by which plants use light energy to make glucose. It needs energy from the photons of light and it is their anabolic effect on the plant that gives the energy for the reaction to take place. During this process ...
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B.
To investigate the effect of light intensity on the rate of photosynthesis
Procedure 1. 2. 3. 4. Cut the stem of a well-illuminated piece of Hydrilla to about 10 cm long. Place it with cut surface upwards, in a boiling tube filled with 0.25% sodium hydrogencarbonate solution. Set up the apparatus as shown in Fig.1. Stand the tube in a beaker of water at room temperature. Record the temperature of the water, which acts as a heat shield, and check it at intervals throughout the experiment. It should remain constant and the water should be renewed if necessary. 5. 6. 7. Put a 100-watt table lamp at 10 cm from Hydrilla. Turn on the lamp. Wait for about 5 minutes for Hydrilla to equilibrate. Suck the sodium hydrogencarbonate solution from the tube into the pipette. Close the clip and record the initial reading. Make sure that the clip is tightened to prevent the solution in the pipette from falling. 8. After a fixed period of time (e.g. 5 minutes), record the final reading in the pipette and calculate the volume of gas collected. 9. Repeat steps (2) to (8) respectively at other distances (d) of the table lamp from Hydrilla: 20 cm, 30 cm, 40 cm and 50 cm. 10. Plot a graph of the rate of photosynthesis (volume of gas collected per until time) against light intensity (1/d2).
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C. To investigate the effect of carbon dioxide concentration on the rate of photosynthesis Procedure 1. 2. 3. 4. Cut the stem of a well-illuminated piece of Hydrilla to about 10 cm long. Place it with cut surface upwards, in a boiling tube filled with 0.1% sodium hydrogencarbonate solution. Set up the apparatus as shown in Fig.1. Stand the tube in a beaker of water at room temperature. Record the temperature of the water, which acts as a heat shield, and check it at intervals throughout the experiment. It should remain constant and the water should be renewed if necessary. 5. 6. 7. Put a 100-watt table lamp at 10 cm from Hydrilla. Turn on the lamp. Wait for about 5 minutes for Hydrilla to equilibrate. Suck the sodium hydrogencarbonate solution from the tube into the pipette. Close the clip and record the initial reading. Make sure that the clip is tightened to prevent the solution in the pipette from falling. 8. After a fixed period of time (e.g. 5 minutes), record the final reading in the pipette and calculate the volume of gas collected. 9. Repeat steps (2) to (8) respectively at other concentrations of sodium hydrogencarbonate solution: 0.15%, 0.2%, 0.25%, 0.3% and 0.4%. 10. Plot a graph of the rate of photosynthesis (volume of gas collected per until time) against concentration of sodium hydrogencarbonate solution. 11. From the graph, determine the concentration of the sodium hydrogencarbonate solution at which the volume of gas collected begins to level off. 12. Repeat steps (2) to (11) using a higher light intensity by putting the table lamp at a closer distance.
The Essay on Dconcentrations Of Solutions Determine The Mass Of A Potato
Introduction: The way to get the full results of this lab was through the process of osmosis. Osmosis is the movement of water across a membrane into a more concentrated solution to reach an equilibrium. When regarding cells osmosis has three different terms that are used to describe their concentration. The first of these words is isotonic. Cells in an isotonic solution show that the water has no ...
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D. To investigate the effect of temperature on the rate of photosynthesis Procedure 1. 2. 3. 4. Cut the stem of a well-illuminated piece of Hydrilla to about 10 cm long. Place it with cut surface upwards, in a boiling tube filled with 0.25% sodium hydrogencarbonate solution. Set up the apparatus as shown in Fig.1. Stand the tube in a beaker of water at room temperature. Record the temperature of the water, which acts as a heat shield, and check it at intervals throughout the experiment. It should remain constant and the water should be renewed if necessary. 5. 6. 7. Put a 100-watt table lamp at 20 cm from Hydrilla. Turn on the lamp. Wait for about 5 minutes for Hydrilla to equilibrate. Suck the sodium hydrogencarbonate solution from the tube into the pipette. Close the clip and record the initial reading. Make sure that the clip is tightened to prevent the solution in the pipette from falling. 8. After a fixed period of time (e.g. 5 minutes), record the final reading in the pipette and calculate the volume of gas collected. 9. Repeat steps (2) to (8) respectively at other temperatures: 5°C, 10°C, 15°C, 25°C, 30°C, 35°C and 40°C. 10. Plot a graph of the rate of photosynthesis (volume of gas collected per until time) against temperature. Note 1. For any change in the experimental conditions of the above investigations, it is necessary to allow the plant to equilibrate before taking any reading.
The Term Paper on Boiling Tube Reaction Temperature Solution
PLANNING Investigating the Kinetics of the reaction between Iodide ions and Peroxodisulphate (VI) ions By the use of an Iodine clock reaction I hope to obtain the length of time taken for Iodine ions (in potassium iodide) to react fully with Peroxodisulphate ions (in potassium Peroxodisulphate). I will do three sets of experiments changing first the concentration of iodide ions, then the ...
