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Enzyme Investigation.

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Enzyme Investigation PLAN Protease enzymes are produced in three different areas of the alimentary canal. These three areas are the mouth, stomach and small intestine. The enzyme in the mouth is the saliva produced in the mouth. It acts on chewed pieces of food, beginning the process of digestion. The food leaves the mouth when swallowed and begins to travel down the oesophagus. Muscles in the walls of the oesophagus contract rhythmically to move food from the throat to the stomach. This contraction is the process called peristalsis. When food reaches the stomach physical digestion occurs where there are continual churning movements of the muscular walls. These churning movements reduce food to a creamy paste called chime. Chemical digestion occurs by enzymes and acids being released by the cells of gastric glands. Pepsinogen is firstly released into the stomach. Hydrochloric acid converts the pepsinogen into the enzyme which catalyses the hydrolysis of proteins into polypeptides. The chime is then released a little at a time into the duodenum, which is the first few centimetres of the small intestine. ...read more.


In the experiment that will be carried out, water is going to represent the condition of the mouth, hydrochloric acid will represent the conditions of the stomach and sodium carbonate for the small intestine. By adding the extracted enzyme and a piece of exposed film to each of the three substances it will be possible to find out which part of the gut the enzyme has been extracted from. For example, if a piece of exposed film started to go clear more effectively in hydrochloric acid, this would mean the enzyme originated from the stomach. The temperature throughout the body stays constant so it would be impractical to change temperature throughout the experiment. My final hypothesis is that the extracted protease enzyme is; * A mouth enzyme if it prefers neutral conditions * A stomach enzyme if it prefers acidic conditions * A intestinal enzyme if it prefers alkaline conditions Equipment that will be used to carry out this experiment * Water bath * Three test tubes * Hydrochloric acid * Sodium carbonate * Exposed film * Extracted sample of enzyme * Beakers * Pipettes * Measuring cylinder METHOD In this experiment the temperature must be kept constant. ...read more.


RESULTS First attempt 5cm of solution at 39 c Time taken to become clear HCl 25 minutes Na2CO3 No change H2O No change DISSCUSION By carrying out this investigation my first set of results show that the enzyme prefers and works best in acidic condition. Looking back at my hypothesis my results show that since the enzyme prefers to work in acidic condition it is a stomach enzyme. The hydrogen bonds of the enzyme in the water and sodium carbonate broke and reformed again in a different arrangement. This was due to the unsuitable pH levels of the solution. The substrate did not bind to the enzyme because the active site did fit the substrate correctly. This causes the reaction to slow or most likely stop. The hydrochloric acid was at the correct pH for the enzyme to work in. The shape of the enzyme was not distorted so the substrate fitted into the active site of the enzyme easily and the substrate was broken down. By taking into account the results of my first attempt my final conclusion is that Enzyme was a stomach enzyme and therefore must have been extracted from the stomach. ...read more.

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