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Factors That Affect Pepsin Investigation.

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Factors That Affect Pepsin Investigation Aim: is to find out what factors affect pepsin Introduction: What It Is & How It Works Enzymes are proteins that speed up chemical reactions in our bodies Enzymes control how much and when a reaction occurs. Enzymes prevent reactions from occurring spontaneously. Pepsin is a protease enzyme that breaks down food or further breaks down a product and is the main protease found in the mucosal lining of the stomach ( which protects it) and is called the chief cells. It also is used to break down proteins into smaller molecules called polypeptides. The enzymes are inactive when there is no food in the stomach and when there are the proteins of the food enter and it turns them on. It works best at body temperature or slightly higher. The pepsin enzyme breaks down protein into polypeptides and then is released as amino acids which can be absorbed by the intestinal lining. This process can only work if it is active, therefore acidic and wet conditions are ideal. It is non-active in alkaline conditions. To keep the acidity level stable hydrochloric acid is produced by the gastric mucosa and maintains the acidity level for pepsin to work. Once the food and gastric juices have reached the intestines the enzymes are neutralised. An enzyme works first by a substrate entering the active site (as shown in diagram 2) ...read more.


take the Bunsen burner away. The reason why we heat the water inside the beaker to 37*C is because pepsin works well in body temperature. It would be too slow at room temperature. 4. The forth step is pick up both of the test tubes which are full of Albumin and Pepsin and place them side by side in the beaker, this should be done quickly as the water inside the beaker might cool down. Once the test tubes are in the beaker then take out the thermometer from the beaker and place it in one of the test tubes to see the temperature. Keep the thermometer in there and wait till it reads 37*C in the test tube. Then take out the thermometer from one of the test tubes and place it in the other and when that test tube is at 37*C then can carry on to the next step. We heated the water first to make it accurate in temperature conditions because if we used a Bunsen burner to heat up a test tube on a blue flame full of enzyme it would denature it very quickly leaving us with little time to take it away from the Bunsen. 5. The fifth step is to get a small piece of paper (at least 3cm long and wide) and draw a round small dot in the centre of it. This is to see when the test tube goes clear and the two liquids are mixed to formed bonds. ...read more.


Conclusion I found investigating the ph quite straight forward as there wasn't much in it to investigate in my opinion. I made a couple of alterations as I was going through my method I changed it by recording one result when the pepsin in the test tube goes clear instead of recording a result every 5 minutes because there isn't any point as it is much easier to get one result every time you do the experiment. I was right in my prediction that the conversion process was short and that If I put an alkali in (when the bonding process is activated) it would slow it down and gradually denature it. I found out that the enzyme mostly works well only at limited ranges of temperature and pH. I also found out that extremes in pH can disrupt the hydrogen bonds that hold the enzyme in its three-dimensional structure, denaturing the protein. I was right in my prediction that the optimum acidic of normal gastric juice was conditions that were the most suitable for the conversion. The enzyme is neutral when there is enough that has been taken away from the substrate. I found out that the temperature can get up to 50*C and not denature. Overall pepsin is a specific enzyme for converting substrate (which is the amylase protein) into polypeptide that is released as amino acids. Zohaib Khan Factors Of Pepsin Investigation ...read more.

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