As the Stomach Churns

Day 1:

In Science class, we did a lab that showed how digestions occurs in the stomach. We used hydrochloric acid dilute, pepsin, water, and cubed egg whites. The hydrochloric acid dilute, pepsin, and water represented the chemicals in our stomach. The egg whites represented the food we are digesting. We had four test tubes that represented four different stomachs. In test tube A, we put the pepsin and three egg whites. Our test tube A had no immediate reaction. Then, we put water, pepsin, and three egg whites in test tube B. Test tube B did not have any immediate reaction other than the water going to the top and the pepsin sinking to the bottom. Next, we put hydrochloric acid dilute and three egg whites in test tube C. This test tube did not have any immediate reaction. Lastly, we put hydrochloric acid dilute, pepsin, and three egg whites in test tube D. This test tube also did not have any immediate reaction. After each test tube, we used litmus paper to test which test tubes were acidic. Test tube A and test tube B were not acidic because the blue litmus paper did not turn pink when it came in contact with the substances inside the test tubes. However, the blue litmus paper turned pink when it came in contact with the substances in test tubes C and D. This is because both of these test tube held hydrochloric acid dilute.

Day 2:

When we came back to science class today, we observed the test tubes again. In test tube A, the egg whites did not dissolve. Instead, the pepsin inside froze and hardened around the egg whites. The next test tube, test tube B, had some change. The pepsin dissolved into the water making it foggy. The egg whites seemed to have shrunk by the smallest amount. In test tube C, there was no reaction. The egg whites did not shrink. When we got to test tube D, we saw a significant change compared to the other test tubes. In our test tube, the egg whites shrunk and the piece were coming off from it. Lastly, we used the blue litmus paper. Again, test tubes A and B did not make the litmus paper turn pink. However, the substances inside test tubes C and D made the blue litmus paper pink. Looking at test tubes A and C, I can confirm that the pepsin and the hydrochloric acid dilute are not powerful by themselves. When they are combined, however, they can do much more. This is shown in test tube D. In this test tube, the hydrochloric acid dilute and the pepsin were combined. In just one day, you could a significant difference from the day before.