Enzyme Activity Ia Essays

Enzyme Activity Ia Essays Enzyme Activity Ia Essay Enzyme Activity Ia Essay Year 11 IB Biology IA Report 2011 5/31/2011 Enzyme Activity Experiment Introduction3 AIM3 Materials3 Method4 Result5 Table 1:5 Table 2:5 Graph 16 Discussion6 Conclusion8 Bibliography9 Appendix 1 (Test tube 3- 45 degrees)9 Appendix 2 (Test tube 1- 5 degrees)9 Appendix 3 (Test tube 2- 20 degrees)9 Introduction Phenolphthalein is an indicator that is pink in alkaline solutions of about pH10. When the pH drops below pH 8. 3 phenolphthalein will go colourless. Here, an alkaline solution of milk, lipase and phenolphthalein will change from pink to colourless as the fat in milk is broken down to form fatty acids (and glycerol) thus reducing the pH to below 8. 3. The time taken for this reaction to occur is affected by temperature. AIM To investigate the effects of increasing temperature on the activity of enzyme Lipase. Materials * Milk, full-fat or semi-skimmed, 5 cm3 per student per temperature assessed * Phenolphthalein in a dropper bottle (see note 1) * 5% lipase solution, 1 cm3 per student per temperature assessed * Sodium carbonate solution, 0. 05 mol dm-3, 7 cm3 per student per temperature assessed * Electric hot water baths set to a range of temperatures, each containing a thermometer, a test-tube rack and a beaker of lipase solution. * Ice * Marker pen * Test tube rack * Measuring cylinder (or syringe), 10 cm3, 2 * Beaker, 100 cm3, 2 (for milk and sodium carbonate solution) * Beaker, 250 cm3, 2 (to act as water baths for temperatures below room temperature) * Thermometer * Test tube * Glass rod * Syringe, 2 cm3 * Stop clock/stopwatch Method 1. Label a test tube with the temperature to be investigated. 2. Add 5 drops of phenolphthalein to the test tube. 3. Measure out 5 cm3 of milk using a measuring cylinder (or syringe) and add this to the test tube. 4. Measure out 7 cm3 of sodium carbonate solution using another measuring cylinder (or syringe) and add this to the test tube. The solution should be pink. 5. Place a thermometer in the test tube. Take care as the equipment could topple over. 6. Place the test tube in a water bath and leave until the contents reach the same temperature as the water bath. . Remove the thermometer from the test tube and replace it with a glass rod. 8. Use the 2 cm3 syringe to measure out 1 cm3 of lipase from the beaker in the water bath for the temperature you are investigating. 9. Add the lipase to the test tube and start the stopclock/ stopwatch. 10. Stir the contents of the test tube until the solution loses its pink colour. 11. Stop the clock/ watch and note the time in a suitable table of r esults. Result Table 1: | Test tube 1 5 degrees| Test tube 220 degrees| Test tube 345 degrees| Test tube 465 degrees| Time (min: sec: usec)| 31:04:86 ()| 16:26:17| 2:09:03| 32:20:74 ()| Notes| The test tube was breakdown before the liquid (milk) turns white| Complete| Complete| The liquid didn’t turn white, and colour of the liquid (Milk) was light pink| Table 2: Time (Min)| Test Tube 15 degrees| Test tube 220 degrees| Test tube 345 degrees| Test tube 465 degrees| 00:00:00| | | Light pink| | 02:00:00| | Pink | Completed| | 04:00:00| | | | Turn light pink| 06:00:00| | Light pink| | | 08:00:00| Turned light pink| | | | 10:00:00| | | | lighter| 2:00:00| | White with Pink| | | 14:00:00| Lighter| | | White with pink| 16:00:00| | Completed| | | 18:00:00| | | | | 20:00:00| | | | | 22:00:00| | | | | 24:00:00| | | | | 26:00:00| Really Light pink| | | | 28:00:00| White with pink| | | | 30:00:00| | | | | Graph 1 Discussion As the introduction of this report shown that the phenolphthalein is an indicator that is pink solution of about pH10, and when the pH drops below pH8. 3 phenol phthalein goes colourless. Through this report, the aim is to investigate the effect of increasing temperature on the activity of the enzyme lipase. The data of the experiment results showed that the sample [Test tube 1] in five degrees took around 31 minutes and 04 seconds to turns into light pink, but the testing wasn’t complete, as the test tube was break down before it completed, but record from another group’s result, it took around 50 minutes for the sample to completely turn white. (Result from Sumin’s group). The sample [Test tube 2] in 20 degrees took around 16 minutes and 26 seconds to complete the reaction and completely turned white. The sample [Test tube 3] took around 2 minutes and 09 seconds to complete the reaction and this sample took the shortest time to complete the reaction. The sample [Test tube 4] took around 32 minutes and 21 seconds to turn into very light pink (White with pink), but it didn’t complete the reaction as the time was run out. As the result, it shows that the temperature between 20 to 45 degrees is the best environment for the fat in milk to broken down to fatty acids and glycerol thus reducing the pH to below 8. and the taken time will increase if the temperature is over 45 degrees and the lipase might not break down the fat in milk or not work at all. The temperature affected the action of the fat breaks down to fatty acids and glycerol (lipase) in this way because when the temperature increase and then the time taken for the reaction will also increase by increase the collision rate between the substrate molecules and enzymes. The fastest time for the reaction is at the suitable and advantageous temperature for the enzymes which is between 20 to 45 degrees (Â ± 5 degrees). The time taken for the reaction will decrease from 5 degrees to 45 degrees, but the time will increase since the temperature is reach and over 45 degrees, as the protein structure of the enzyme will denatured by the high temperature and the enzyme is de-activated and the molecule is lose its shape. (University of Maryland Medical Center, 2009) Recording from the experiment result, the best temperature for the fat in milk breaks down to fatty acids and glycerol is between 20 to 45 degrees and it might not work really well when the temperature is over 45 degrees. On another hand, there are some weaknesses need to be improve in the experiment. Firstly, the water temperature for the Test tubes to stay in was under/ over the temperature that was suggest in the experiment as the temperature of the water was hard to control as the exactly temperature that the instruction suggested, so the group was recommend that a member from the group needs to add extra hot water/ extra ice when the temperature of the water is under/ over the temperature recommended. Secondly, the group set up and put all the test samples in the test tube at the beginning of the experiment and suddenly left the samples in the room temperature for almost 10 minutes before the group start the experiment; therefore, the results from the experiment might be wrong as the solution in the test tube might affects the lipase during the break time. As the result, the group suggest to mix up the solution and the test samples before the experiment starts, and the break time gap is not allowed. Thirdly, the syringe wasn’t used to measure out the lipase, so the group chose to restart the experiment as the results may have changed. However, after restarting the experiment as a whole, the experiment was a lot more successful and there was more care. Finally, these improvements will be use as a reference in the next class experiment. Conclusion In conclusion, the results from the experiment shown that the best temperature for the fat in milk to break down to fatty acids and glycerol is 45 degrees and the reaction will not work really well since the temperature are over 45 degrees. Also, recording from the graph, the test tube 3 (45 degrees) spent less time to complete the process and the test tube 4 (60 degrees) spent more time to turn the colour of the liquid into light pink and the process/ reaction didn’t complete in the end. As well, the information shown at the website of the University of Maryland Medical Centre displayed that the protein structure of the enzyme will denatured by the high temperature and the enzyme is deactivated and the molecule is lose its shape when the temperature is over 45 degrees. University of Maryland Medical Center, 2009). As the result, when the temperature increase from zero degrees to 45 degrees, the time taken for the reaction will decrease, but the reaction starts slow down since the temperature is reach and over 45 degrees. Bibliography University of Maryland Medical Center. (2009). Retrieved from Lipase: umm. edu/altmed/articles/lipase-000311. htm Appendix Appendix 1 (Test tube 3- 45 degrees) Appendix 2 (Test tub e 1- 5 degrees) Appendix 3 (Test tube 2- 20 degrees)