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Investigate How Temperature Affects the Reaction between Milk and Trypsin.

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An Experiment to Investigate How Temperature Affects the Reaction between Milk and Trypsin Planning Diagram Equipment List Thermostatic Water Bath Beaker x2 Thermometer Trypsin 2.5ml Milk 2.5ml Measuring Syringe 5ml Stop Clock Method When Milk and Trypsin are put together, Trypsin which is an enzyme breaks down the milk; this process is affected by several things. I could change the temperature the experiment is done at, the amount of Trypsin used or the concentration of the Trypsin. I have decided to change the temperature of the experiment. First I will put 2.5 ml of Trypsin and 2.5 ml of milk in separate beakers into a water bath at a temperature of 70oC under the beaker of milk I will put a piece of laminated card with a cross on. I will put a thermometer in both beakers and when temperatures reach 70oC, I will pour the Trypsin into the milk beaker. I will then start timing until I can see the cross under the beaker and record the time. I will do this again at a temperature 60oC, 50oC, 40oC and finally 30oC. I will then repeat this three times to get an average of my results which I will convert into rate which I will use to plot on a graph. ...read more.


I did not have any anomalous results. Here are the results that I collected in the main table. I will plot these results on my graph: Time taken until cross is visible (s) Temperature (oC) Result 1 Result 2 Result 3 Average 30 240 225 247 237 40 47 48 51 49 50 75 105 86 89 60 116 120 108 115 70 192 212 194 199 80 360+ 360+ 360+ 360+ I then converted my averages in to rate, I will plot the rates on my graph: Temperature (oc) Averages (s) (0dp) Rate (S-1) (4dp) 30 237 0.0042 40 49 0.0204 50 89 0.0112 60 115 0.0086 70 199 0.0050 80 360+ 0.0027 I have '360+' in the table because the trypsin did not digest the milk after 360 seconds, this is probably because the trypsin has been denatured and it no longer works. Analysing and Considering Evidence I have found out that at low temperatures and at high temperatures it takes the enzymes a long time to work. At low temperatures, the reaction is slow because enzymes find it hard to work in cold conditions this is because they are used to working in about the same temperate that the body is at and 30oc is to low for the body to be at, so the enzymes find it hard to work. ...read more.


I couldn't use on for several reasons: there was not enough water baths for everyone to use in the class and if I did use one it would take to long to take all of my results as I would have to wait for the thermostatic water bath to get to the correct temperature each time. I solved this problem by putting the milk and trypsin in test tubes, I then put the test tubes in a beaker of water, I heated the water until the temperature of the milk and trypsin is correct, I then put the milk into the trypsin test tube and waited for it to react, I kept the temperature correct with a Bunsen burner. Another problem was the time error in the stop clock. I would have wasted time from when I saw that the milk was digested to when I stopped the clock. This would not have wasted lots of time but it would have wasted some. I could not do anything to solve this problem. Improvements I could have improved my experiment by using more accurate measuring equipment, such as a burette instead of a measuring syringe. I could have used a thermostatic water bath, but this was not possible as I explained above. I could have used an electronic thermometer, as this would be more accurate than a normal one. Daryl Breakwell 11KR Biology Coursework Page 1 of 7 ...read more.

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