Monday, November 7, 2011

"As the Stomach Churns" Lab Response

        In the first day of this lab, we were seeing how the hydrochloric acid in our stomach digests our food and how acidic conditions affect protein digestion. 
       The first step was taking four test tubes and labeling all of them a different letter: A, B, C, and D. Then hard boiled egg-whites were cut into three centimeter pieces and three pieces was put in each of the four test tubes. After that process has been completed, we continued on putting either pepsin, or hydrochloric acid in different test tubes and seen what reaction occurred:
       For test tube A, with only pepsin and eggs, the immediate reaction that occurred was that the eggs started to turn a yellowish color and looked almost as if it were liquid.
       In test tube B, the water turned white and everything turned into a mushy substance (This was the tube that had the pepsin and water with the eggs).
       Test tube C had no immediate reaction, and this was the tube that had only hydrochloric acid with the eggs.
         Finally, test tube D had pepsin, the acid, and the eggs. Immediately, it felt as if the substances were bubbling lightly and started to form a white layer on the top as well as turning a clear white color.
       
         After testing all of this, we tested each of these solutions on purple-colored litmus paper. Test tube A made the paper look oily, but the paper was still purple. Test tube B made the paper look sort of a blue color. And test tubes C and D made the paper turn pink.
       Based on these observations, one day just isn't enough for out stomach to digest its food. This is why none of the test tubes had any major reactions right away. My prediction would be that maybe by the second day, the eggs will start to break down, and I think that test tube D will be the first of it. This  is because, this was the only test tube that had both the acid and pepsin added and it made a bubbly reaction, which made me think that the acid started doing something with the eggs, and possibly already starting to break it down. Also, there is hydrochloric acid in our stomachs so test tube A and B had no acid so it's least likely that any of those test tubes would start "digesting" first.

Thursday, November 3, 2011

Sugar Cube Lab

This was a quick lab that was completed in class. The purpose of this lab was to see an example of digestion and how to speed it up:


First, a test tube was taken and a sugar cube was placed into it. Second, in another test tube, a sugar cube that has been crushed to little pieces was put into it. Third, both test tubes were filled with the same amount of water and were shaken for one minute. As the test tubes were shaken, the test tube with the crushed sugar cubes dissolved in the water first. 
By observing what happened, I was able to conclude that when eating, chewing your food first will help speed up digestion because the food is already  broken down and that it's less work when it reaches the stomach. However, if people were to swallow their food whole, digestion would be much slower because the stomach still has to break down the food.
 In other words, food that has already been crushed, digests faster than food that is still whole.