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Digestion Lab discussion

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Discussion: The basic idea of the lab is to conduct an experiment observing gastric digestion, intestinal digestion of starch, intestinal digestion of proteins and lipids, and absorption in the small intestine in order to understand the process of digestion. The conditions of the gastric digestion test included being placed in an incubator at 37-40�C for 45 minutes. 5 ml of pepsin solution, hydrochloric acid, and artificial gastric juice each were added separately to each test tube. After it was removed from the incubator, six drops of Biuret reagent was added to each test tube. For the intestinal A digestion of starch test, conditions included adding 5 ml of starch solution to each test tube. Each tube was filled with starch solution, but the conditions in which they remained differed; test tube 1 was left in room temperature, test tube 2 was placed in a 40�C incubator, and test tube 3 was placed in a 75�C water bath. After, three drops of iodine-potassium iodine solution were added to all three containers. The conditions for the intestinal digestion of proteins and lipids included adding 10 ml of litmus milk solution was added to each test tube. ...read more.


In the presence of starches, iodine-potassium iodine changes from bright yellow to blue-black. In the test tubes, the presence of starch is indicated by a purple-black color. The absence of starch is indicated by a light brown color (Carolina Biological, 2005). Individual results included that for test tube 1 which was placed in room temperature, a blue or blackish color occurred indicating the negative presence of digestion. In test tube 2 which was placed in an incubator was observed to be blue and blackish also, which tested negative for digestion. Test tube 3 which was placed in the water bath resulted in a blue and blackish color also. For group results, 4/4, or 100% of the groups tested negative for digestion in test tube 1 which was not predicted, 4/4, or 100% of the groups tested negative in test tube 2 which was not expected, and 4/4, or 100% of the groups tested negative for digestion in vial 3 which was predicted. For intestinal digestion B, it is hypothesized that litmus milk will change color in the presence of pancreatin indicating digestion, but not in the presence of distilled water. ...read more.


Another improvement that could be made would be to control the room temperature to an exact degree in order to record and control precise results when dependent on room temperature for a condition in a test. A new idea that could be made to this lab would be to test each of the different tests in cold temperatures or conditions to see if that has any affect on the digestion. Conclusion: It is hypothesized that protein digestion will occur in the presence of gastric juice but not in pepsin or hydrochloric acid; pancreatic juice will digest starch at 22�C room temperature and 40�C body temperature but not at temperatures greater than or equal to 75�C; litmus milk will change color in the presence of pancreatin indicating digestion. Furthermore, it is hypothesized that sugar will pass through dialysis tubing but starch will not (Taylor, 2009). Overall, the data supports the hypothesis as it was shown to support 77.50% of the hypothesis statement. I enjoyed this lab because I thought it was interesting to see the entire color changes indicative to the many conditions and factors that went into each test. ...read more.

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