1. 2-7-11 In What happens to a carbon atom over time?

2. 2-7-11 Through  Post lab OUT Study for your test!!

3. Procedure 1. Obtain a sprig of Elodea 2. Remove a few leaves from the cut end. 3. Fill test tube halfway

4. 4. Gently slide plant into test tube, top side down. 5. Add water until Elodea is completely submersed. 6. Place test tube into test tube rack. 7. Place 75 watt lamp 5cm from heat sink. 8. Turn lamp on for 2 minutes. 9. Begin counting the number of oxygen bubbles for 3 minutes.

5. 10. Run a second three-minute trial. Record results and average. 11. Turn lamp off and move it back so it is 20 cm from plant. 12. After 2 minutes, turn lamp on and record bubbles for two three-minute trials. 13. Record results and average. 14. Discard water and use water with dissolved sodium bicarbonate. sodium bicarbonate sodium carbonate + water + carbon dioxide

6. 15. Count bubbles for two 3 minute trials. 16. Record results and average. 17. Graph results

7. Observations and Data Table Number bubbles ofOxygen Trial 1 (3min) Trial 2 (3 min) Average Lamp 5 cm from plant Lamp 20 cm from plant Lamp 5 cm away with CO 2

8. Graphs Complete a graph for this experiment Groups on the X-(5cm, 20 cm, 5 cm with CO2 Number of bubbles on the Y

9. Post lab 1. What is being used in this investigation to determine the rate at which photosynthesis is occurring? 2. How did the number of oxygen bubbles (rate of photosynthesis) change as the light source was moved from a distance 5 cm to 20 cm? 3. How did the rate of photosynthesis change when sodium bicarbonate was added to the Elodea plant 5 cm from the light?

10. Conclusion Write a conclusion for this lab Was your hypothesis correct? What does your data show? What was the most important learning component from this lab? What would you do to change the experiment?