Cellular respiration is a fundamental concept in biology. Our CO2 and O2 Gas Sensors make it easy for your students to study this concept, producing excellent data, as shown above. However, you can’t just place a few peas in a chamber and expect to see great results when using both sensors at the same time. Our resident biologists have recently revisited the “Cellular Respiration” experiments in Biology with Vernier and Advanced Biology with Vernier to provide you with the following tips and tricks for consistently good results when using both sensors.
- For best results, you should follow the Teacher Information, which calls for using peas that have been allowed to germinate for three days. However, you can still get very good data with peas that have been soaked for 12−24 hours. You just need to use more peas.
- Blot the peas with a paper towel before you put them in the chamber. Excess water vapor can interfere with both sensors.
- Use the BioChamber 250 as the sample chamber, and fully line the bottom with peas to maximize the number of peas in the chamber. Twenty-five peas work fine if you are just using the CO2 Gas Sensor. But we recommend using at least 40−50 peas if you want to see significant changes in oxygen concentration. This is very important, especially if you are using peas that have only been germinating for 12−24 hours.
- Oxygen levels are very high in ambient air (20.9%) and your students are measuring a relatively small change in concentration over time in this experiment. This change will be much easier to observe if your students change the units to ppt or ppm. By following these suggestions, you and your students should get good results when using the CO2 and O2 Gas Sensors at the same time.