Enzyme+Action+Lab+Report

Investigating the effect of temperature and pH on enzyme action
 * Biology Lab Report

Prediction and results:

Part A  ** **Part B**
 * **Test-tube** || **Content** || **Conditions** || **Prediction of iodine test** || **Iodine test** || **Conclusion** ||
 * A1 || 5cm 3 of starch + 3cm 3 of amylase || Ice water || Blue-black || Purple || Digestion has not occurred ||
 * B1 || 5cm 3 of starch + 3cm 3 of amylase || 37°C || Brown || Brown || Digestion has occurred ||
 * C1 || 5cm 3 of starch + 3cm 3 of amylase || Boiling water || Blue-black || Blue-black || Digestion has not occurred ||
 * D1 || 5cm 3 of starch + 3cm 3 of distilled water || 37°C || Blue-black || Blue-black || Digestion has not occurred ||
 * **Test-tube** || **Content** || **Temperature** || **Iodine test (before)** || **Iodine test (after)** || **Conclusion** ||
 * W || 2cm 3 of starch solution + 2cm 3 of HCL + 2cm 3 of amylase || 37°C || Blue-black || Blue-black || Digestion has not occurred ||
 * X || 2cm 3 of starch solution + 2cm 3 of distilled water + 2cm 3 of amylase || 37°C || Blue-black || Brown || Digestion has occurred ||
 * Y || 2cm 3 of starch solution + 2cm 3 of NH 4 OH + 2cm 3 of amylase || 37°C || Blue-black || Blue-black || Digestion has not occurred ||
 * Z || 2cm 3 of starch solution + 4cm 3 of distilled water || 37°C || Blue-black || Blue-black || Digestion has not occurred ||

Part A Digestion had occurred in Tube B as there was a presence of amylase which is an enzyme that broke down the starch. Digestion, however, did not occur in Tube C and D which remained blue-black in colour after the iodine test. The temperature was too high in tube C which could have caused the enzymes to be denatured and thus can no longer bind to the starch and break it down. There was an absence of amylase to break down the starch thus it remained blue-black after the iodine test. Tube D served as a control set-up to prove that the change in results were caused by the changed factors. I would use the Benedict's solution test to detect the presence of sugar produced as a result of the reaction in Tube B. In conclusion, as temperature rises, the rate of chemical reactions increases. This leads to more interactions between an enzyme and its substrate. However, amylase activity would increase as the temperature rises until a certain high temperature at which the amylase would denature and be non-functional.

Part B Digestion had occurred in Tube X as there was a presence of amylase which is an enzyme, to break down the starch. Tubes W, Y and Z remained blue-black after undergoing the iodine test. The pH of Tube W was too low which could have caused the amylase to have denatured. However, in Tube Y, the pH was too low which could have caused the reaction to have taken a longer time to occur. In Tube Z, there was an absence of enzymes to break down the starch. In conclusion, there is an optimum pH level for which digestion occurs fastest. The further the pH is from the optimum, the slower the reaction would take place until the pH is too low or high where the amylase would denature and be non-functional.