Cellular Respiration Lab

This lab works with peas in order to experiment with and document the results of cellular respiration. Cellular respiration is how a cell breaks down glucose and oxygen to form carbon dioxide and water, but more importantly, 686 kilocalories per mole of glucose is harnessed from the reaction. We worked with both germinated and non-germinated peas and documented how much oxygen was released at different amounts of time. Since the germinated seeds are forming new life which requires energy, they were using more oxygen than the non-germinated seeds which did not require energy (the more oxygen used, the more reactions are happening). By adding water to non-germinated seeds, the seed begins the cellular respiration process and begins to grow because it has access to the energy that is yielded from the reaction.

In order for us to document how much oxygen was used we first had to eliminate the carbon dioxide from the equation because otherwise the measurements of the gas in the pipette would not only be oxygen but carbon dioxide also. To keep this from happening, KOH was added to the respirometer to form two solids when carbon dioxide reacts with the KOH: water and K2CO3. This allowed us to collect the data for how much oxygen was being used without the interference of carbon dioxide. The group I was in conducted the experimented at twenty degrees and our experiment seemed consistent with what was expected: our dry beads’ corrected rate did not change throughout the time intervals which showed that no cellular respiration occurred in the seeds. Since non-germinated seeds are not alive, no cellular respiration should take place. For our warm reading at thirty degrees, we used another group’s data. There are reasons to believe that this data resulted from problems in the experiment because the dry peas’ rate not only changed from interval to interval but was also negative. Because the Q10 is found by using rates from both the thirty and twenty degree trials, our Q10 is not correct either. It was obvious, however, that heat played a role in cellular respiration because more oxygen was used even though both trails occurred in the same time scale.