The Effects of Pepsin vs. Trypsin in the Digestion of Protein

9 September 2016

The Effects of Pepsin VS. Trypsin in The Digestion of Protein Introduction As food is mechanically and chemically digested through our oral cavity then passes through our pharynx and down our esophagus, our food then enters the stomach. The stomach, being the main organ for storage, also helps with breaking down our food, but in order to accomplish that our pancreas helps by excreting an inactive digestive enzyme called pepsinogen. Pepsinogen is the inactive form of the more familiar enzyme called pepsin.

In order for pepsinogen to form into pepsin it must first react with the acid HCl breaking it down its layers to reach the active site. To our convenience, HCl is already located in our stomach due excretory glands called parietal cells. As the stomach churns and mixes acid, pepsinogen, and food, pepsin is being created. Pepsin, being its main function to digest protein, is breaking down amino acids into smaller chains of polypeptides until it reaches the small intestine. Leaving the stomach, the partially broken down food (chyme) passes through the pyloric sphincter then enters the small intestine.

The Effects of Pepsin vs. Trypsin in the Digestion of Protein Essay Example

This is the site where all terminal digestion of carbohydrates, proteins, and lipids occur including the absorption of amino acids and glucose. Here, the pancreas then excretes a large amount of bicarbonate and an inactive enzyme call trypsinogen which in turn activates to form trypsin which also helps the breaking down of proteins. But compared to pepsin, trypsin does not activate under acidic conditions where chyme has a very low pH and with that, the bicarbonate neutralizes chyme which allows for activation.

Additional to that, once trypsin is activated, it itself activates other digestive proteases to aid in digestion. Therefore, digestion and absorption can now occur. With that said, the digestion of our body proposes a few questions, one being that if we were to take already activated pepsin and trypsin and conduct an experiment, which enzyme would digest protein more efficiently with the change in pH? Thus the hypothesis of this experiment states that the acid and pepsin will digest protein more ffectively than trypsin and a base. To determine this, the colors will be observed with the help of a polypeptide indicator. Materials and Methods Materials used for this experiment were twelve equal sized test tubes, one test tube rack, a grease pencil, several pieces of egg whites, a pipet, Biuret indicator, and a water bath device. Substances included HCL, distilled water, Na2CO3, pepsin, and trypsin. Methods were as followed: Twelve test tubes were obtained and numbered from one to twelve.

Then they were arranged on a test tube rack into two rows of six. With that, substances were measured and placed into each tube (amounts located on Table 1). Several pieces of egg whites were added to each test tube, mixed, and placed into a 37 degree Celsius water bath for 90 minutes. When the 90 minutes were over, 4 drops or until color is seen of Biuret reagent which is an indicator for polypeptides were placed into each test tube. Lastly, results were recorded. Results Table 1.

Amount of each substance and the change of color after Biuret indicator was added. Abstract Previously, an experiment was conducted to determine the performance of raw digestive enzymes with sodium carbonate and hydrochloric acid. With that, the acid and the base was to determine the proficiency of digestion with different pH levels. As a result of the experiment, it proved that the pH level of the acid with the pepsin increased in digestion compared to trypsin and a base or any other substance the enzyme was mixed with.

What proved this was the polypeptide indicator which turned test tube number 3 completely pink. With the absence of the color purple suggest that digestion occurred. Discussion The results of this study supports the hypothesis that the digestion of pepsin with HCl digested protein more that trypsin and sodium carbonate. But though this experiment suggested the hypothesis correct, it remains undetermined the reason why trypsin with its base did not work as efficiently.

Possibilities may be that the conditions within the test tubes isn’t comparable to the conditions within our bodies. As previously stated, trypsin is released into the small intestine in order to further digestion of large protein molecules. But addition to trypsin (an activator of many proteases) , other enzymes such as chymotrypsin aids in the digestion of proteins. Though trypsin did appear to have done some digestion within the test tube, it still wasn’t capable of digesting protein on its own. Literature Cited

Mason, Kenneth A. , Jonathan B. Losos, Susan R. Singer, Peter H. Raven, and George B. Johnson. Biology. 9th ed. New York: McGraw-Hill, 20011. 985-89. Print. Class notes George, Helga. “What is trypsin?. ” wiseGEEK. Ed. Michelle Arevalo. Conjecture Corporation, 13 Apr. 2013. Web. 5 May 2013. <http://www. wisegeek. com/what-is-trypsin. htm>. George, Helga. “What is Pepsin?. ” wiseGEEK. Ed. Michelle Arevalo. Conjecture Corporation, 15 Mar. 2013. Web. 5 May 2013. <http://www. wisegeek. org/what-is-pepsin. htm>.

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