Enzyme Lab 8/26/11

My partner for this lab was Ariel.  The purpose of the lab was to test how much oxygen was produced by the enzyme, which in this case was yeast.

The setup for this lab involve a graduated cylinder filled with water and submerged partly underwater upside down. It was submerged in a tub of water. Our reaction chamber was filled with 20 milliLiters of peroxide and plugged with a stopper with a hole in it. In the hole was a rubber tube that was placed in the opening of the graduated cylinder.

Once the set-up was complete, our testing began. We started with one milliLiter of the yeast solution and added it to the reaction chamber and quickly put the stopper in. The second and third tests were the same except for the amount of yeast solution. The second used .75 milliLiters and the third used .5 milliLiters.

Our results for the first test showed that the enzyme produced very little oxygen in the beginning. After recording every 30 seconds for 5 minutes, our results increased and the oxygen bubbles were larger and more frequent. It produced almost 15 milliLiters of oxygen in the end.

Our second and third test's results were similar, starting off slow but gradually increasing in the amount of oxygen. The second test produced a smaller amount of oxygen than the first test. The third test was similar in producing a smaller amount of oxygen than the first and second. However, the results showed that it produced hardly any oxygen at all and only created many very small bubbles instead of a few large bubbles like the other tests.

Based on these results, our conclusion is that the smaller amount of yeast in the solution, the less reaction it will have. It produces less oxygen with each decreasing amount. We believe that some inconsistencies may have been caused due to the amount of peroxide we put in the reaction chamber and the setup. Our very first trial had to be re-done because the stopper popped out of the chamber. Therefore, the results may be inconclusive, but the theory remains the same and valid.

Rolly Polly Lab 8/11/10

This lab assignment consisted of collecting rolly pollys or pillbugs from each students yard.  We then experimented on the creatures by testing different hypothesis's about their habitats and environments.

My group was with Ariel and Dara.  We wanted to test the moisture of the rolly polly's habitat and what drew them to the enviroments we discovered them in.  Our hypothesis was that since the bugs were found underneath rocks and logs that they would prefer a moist habitat rather than a dry one.

To test this hypothesis we used habitat trays with two sections to compare to each other.  We used two pieces of paper, one dry and one wet with tap water.  We then placed 14 rolly pollys in the tray and waited approximately 10 minutes before beginning the test in order to let the bugs adapt to the new environment somewhat.  This would allow them to try out both habitats and then make a decision.  Our group then started recording data every minute, writing down how many bugs were in each habitat. 

The first minute of data we recorded showed that all of the bugs prefered the dry habitat.  However, the next couple minutes showed a split decision with about 9 or 8 bugs on the dry side and 5 or 6 on the wet.  This data confused our group, but as we watched longer, we recorded data that stated that the bugs prefered the dry side the rest of the time. 

During this experiment, we noticed that the rolly pollys grouped together with each other, almost as if they were huddling together to stay warm and sleeping.  Because of this analization, our group believes that it is not the moisture of the environment that the bugs prefer, but rather the temperature or darkness.  However, we ran out of time so we could not test either of these new hypotheses.