Enzyme lab

For the experiment we were testing to see how much oxygen was created in a reaction of yeast and hydrogen peroxide. In order to test this we obtained a tub filled with water a graduated cylinder a ring stand, a rubber stopped a rubber tube and a glass cylinder and the yeast and hydrogen peroxide. We had to fill the tub with water about 3/4ths of the way full and then submerge the graduated cylinder in the water and leave it upside down. we then attached the graduated cylinder to the ring stand while leaving the opening in the water. Then we placed 10 mL of hydrogen peroxide in the glass cylinder. we attached the rubber tubing into the rubber stopper and had it ready to place back on the glass cylinder. we then added 1 mL of yeast and immediately placed the stopper on the cylinder. We had to quickly place the rubber tubing under water and inside the graduated cylinder. we kept track and at 30 second intervals we check the amount of air that had been created by the yeast and hydrogen peroxide reaction by counting the amount of bubbles and the how many mL the water had gone down in the graduated cylinder. we continued to check for 5 minutes. we then repeated this experiment using 1o mL of hydrogen peroxide and .75 mL of yeast.

I was expecting for there to be less air produced in the experiment where there was only .75 mL of water. However, we saw the opposite effect. though the results may show this (see attachment) I believe there may have been some human error. I think that there was air already trapped inside the rubber tubing and it was released into the graduated cylinder. Meaning that there was a significant amount of air that had been measured that was not created by the hydrogen peroxide/yeast reaction.

*Note- I had issues uploading the data table so it will be in an e-mail

For my experiment I was investigating whether the pill bugs would prefer a damp environment with living grass or an environment with dead molded grass. In order to test this I had to create each of these environments inside a testing tray. On both sides of the dish I placed a wet coffee filter and then placed dead grass on one side and then the living grass on the other. We released the pill bugs in the center of the tray and began timing. Every three minutes we counted the amount of pill bugs on each side. We continued doing this until 18 minutes had elapsed. Throughout the entire experiment it was obvious that the bugs preferred that dead molded grass as opposed to the living fresh grass. From the beginning of the time to the 9-minute marking there were 5 pill bugs in the dead grass and 3 in the living grass.  After that it remained split into 6 in the dead grass and 2 in the living grass until the 18 minute marking at which there were divided back into 5 in the dead grass and 3 in the living. Though these results seem to be rather convincing that pill bugs prefer dead molded grass you must also take into consideration the outside factors. For example, these bugs could have very well been extremely stressed out due to being contained in this area and having prior to the experiment been removed from an environment in which it was comfortable and then being trapped in a small container for several hours. Also there had to be some human interference due to the fact that the pill bugs were constantly trying to escape. We constantly had to push the bugs back into the testing tray. Despite these flaws the results were what I expected. Because I had found the pill bugs in an environment that had damp molded grass it would only make sense that they would prefer this environment.