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Investigation into the effect of temperature on the digestion of fat by Lipase.

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Investigation into the effect of temperature on the digestion of fat by Lipase: by Chris Lisle Lipase is an enzyme- enzymes are biological catalysts made up from protein. Catalysts speed up the rate of reaction in an experiment without using itself up. Enzymes can be denatured at conditions of high pH or temperature this occurs because increased temperature causes the molecules of the enzymes to vibrate so violently that they break their weak bonds. Enzymes also have an optimum temperature of 37 which is about body temperature, which explains why they work very well within the human body. The process of the digestion of fat by lipase will be maintained by using the pink phenolphalein, coloured pink- which will turn colourless when in acidic conditions. In order to show the phenolphalein at a pink colour it must be regulated at an alkaline pH in order to do this we must add Sodium carbonate to give an alkaline pH. ...read more.


The phenolphthalein turns colourless due to the production of acid throughout this experiment. Fat -----------> fatty acids + Glycerol. The aim of this experiment is to discover the effect of temperature on the digestion of fat by lipase. The Independent variable in this investigation is temperature the other factors will remain the same to see what effect the temperature will have on the dependent variable digestion. I will test the digestion of fat in the following temperatures: 20 ,30 , 40 , 50 , 60 ,this is because the range covers the optimum temperature of an enzyme's rate of reaction and also allows it to experience high temperatures. Method: 1. Place in a test tube. 3cm milk 1cm lipase 3drops phenolphalein 2cm Sodium carbonate 2. Place the test tube in a water bath at room 20 . 3. Using a stopwatch time how long it takes for the colour to change from pink to colourless. ...read more.


The results above do not show the relationship between digestion of fat by lipase and temperature to that I would have hoped. The table of results show that the fastest reaction in this experiment was 60 These results do not confirm my prediction that enzymes would work best at around body temperature. However as the enzymes haven't been denatured it shows that the enzymes must have been more heat stable- this can depend on a number of things- for example how old the enzymes are. Evaluation. I believe that I worked well throughout this experiment and although my results did not follow my prediction that they are a "one off" dependent on the nature of the enzyme. I think this experiment could have been improved by using a computer to time the experiment and use a computerised thermometer to check the temperature of the water baths to more accuracy. You could test this experiment for another type of food e.g. sugar using benedict's solution at different temperatures to see if the enzyme followed the same pattern or followed my prediction. ...read more.

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