BIOLOGY -ENZYME LAB- (Effect of temperature)

Group Member (10/10) Sittipun Suwanmanee Kammanat Lohisathan Natwadee Pattanaphnitchkul Sasicha siriwong Thanaphat Tangroek Wassawan sangkapong

Aim of the experiment To find out the effect of temperature on enzyme activity.

Background In this experiment we used urease enzyme in soya bean to breakdown urea into ammonia and carbon dioxide. We can detect the presence of ammonia by using red cabbage indicator.

Hypothesis We predict that enzyme will denatured in high temperature and in low temperature enzyme activity will occur slowly.

Indicator + sodium bicarbonate Indicator + citric acid Result : Procedure 1 Indicator + water (neutral) Indicator + sodium bicarbonate (Alkaline) Indicator + citric acid (Acid) purple Dark blue Red - pink

Why is it important to have the three reference test tubes? We can indicate whether our results are acid, alkaline or neutral by compare the colour to the reference test tubes. In this experiment positive result should turn blue in colour since ammonium solution is alkaline.

Result : Procedure 2 Indicator + Urea Solution Indicator + Urea Solution + Soya Suspension (Enzyme) Indicator + distilled water + Soya Suspension (Enzyme) purple Dark Blue Purple

Purposes To see whether urease enzyme is working. Only the test tube that contain both enzyme and substrate should show positive result.

Why do we need to add an enzyme into a test tube without urea even though we can predict that no enzyme activity will occur? Because we need to know that whether the indicator going to change the colour when mix with the enzyme. If the solution turn blue then we will have to modify the experiment.

Result : Procedure 3 Placement Temperature( °C ) clarity colour Ice bath clear blue Beaker on hot plate at 245 °C 85 opaque Purple Beaker on hot plate at 360 °C 87 purple Room temperature 22 Blue (before Ice bath) Boiling water 100

Cold temperature slow down the enzyme activity since the solution slowly turn blue. Test tube in room temperature turn blue first which mean it is the most suitable temperature to use urease.

Room Temp Ice Bath

High temperature can cause enzyme to denature High temperature can cause enzyme to denature. We can tell since the solution in high temperature did not turn blue in color. Denatured enzyme caused solution to turn opaque.

Extra information Optimum temperature of urease activity is around 45 – 60 °C We can use this range of temperature to maximize urease activity. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3442171/

CONCLUSION

Conclusion Our hypothesis is true since test tubes that are in high temperature did not show positive result for enzyme activity. Test tube in the ice bath turned blue eventually and the one that turned blue first is the one in room temperature beaker.

Conclusion Enzymes work best in their optimum condition (optimum temperature for this experiment) Too high temperature will cause them to denature and low temperature slow enzyme activity down because particles move slowly in low temperature.

Thank You