Photosynthesis and Respiration Lab
Your group will be either testing for Carbon dioxide or Oxygen. Be sure that you follow the correct instructions for the test that you are doing.
Carbon Dioxide Testing
Materials CO2 sensor – set to Low Spinach leaves Aluminum foil Logger pro Sample chamber
1. Plug in the Logger Pro and connect it to the USB port on the laptop. 2. Connect the CO2 sensor to the channel 1 port on the logger pro. 3. Open the logger pro software on the laptop. 4. Go to the experiment tab at the top of the screen and go to data collection. 5. Set the experiment to collect data for 15 minutes and to take a sample every 5 seconds. 6. Place 4 dry leaves in the sample chamber and insert the probe in the top of the bottle. 7. Completely cover the sample bottle with aluminum foil. Be sure that no light can get in. 8. Wait for 2 minutes and then press collect. 9. Data will be collected for 15 minutes. 10. After collection ends, click on the CO2 graph and highlight the area of the graph that is the most straight. 11. Click on the Linear Fit button to have it calculate the best fit line for your graph. 12. Record the slope of that line as the rate of respiration for your plant. 13. Remove the foil and leaves and make the station ready for the next group.
Oxygen Testing
Materials O2 sensor Sample bottle Spinach leaves Logger pro Light 1. Plug in the Logger Pro and connect it to the USB port on the laptop. 2. Connect the O2 sensor to the channel 1 port on the logger pro. 3. Open the logger pro software on the laptop. 4. Go to the experiment tab at the top of the screen and go to data collection. 5. Set the experiment to collect data for 15 minutes and to take a sample every 5 seconds. 6. Place 4 dry leaves in the sample chamber and insert the probe in the top of the bottle. 7. Place the sample bottle in front of the light – but not so close that the leaves will be burned. 8. Wait for 5 minutes and then press collect. 9. Data will be collected for 15 minutes. 10. After collection ends, click on the O2 graph and highlight the area of the graph that is the most straight. 11. Click on the Linear Fit button to have it calculate the best fit line for your graph. 12. Record the slope of that line as the rate of photosynthesis for your plant. 13. Remove the leaves, turn off the light and make the station ready for the next group.
Data – Record your data and the data for all of the groups in the class. Group Number Rate of respiration Rate of photosynthesis 1
2
3
4
5
Data analysis
1. What is the equation for photosynthesis?
2. Did the spinach leaves do photosynthesis in this lab? What evidence did you see for this?
3. What is the equation for respiration?
4. Did the spinach leaves do respiration in this lab? What evidence did you see for this?
5. Were the rates of photosynthesis and respiration the same for all groups? Why do you think this happened?
6. What organisms do photosynthesis? What organisms do respiration?