1. Lesson Starter
What makes the small intestine perfect for absorption of food?
What is the job of bile?
What 3 enzymes are added by the pancreas?

2. Enzymes

3. Enzymes Biological catalysts Made of protein NOT ALIVE
Can be affected by temperature and pH
Need correct conditions to function properly

4. Temperature Enzymes work best at body temp (37ºC) – OPTIMUM
They work at other temperatures- WORKING RANGE

5. Aim
To find out how changing the temperature affects the activity of an enzyme

6. Apparatus Amylase solution Ice bath Starch solution Water bath @ 35 ºC
4 test tubes
2 syringes
Stop clock
Ice bath
Water 35 ºC
Water bath at 60 ºC

7. Method
Add 10 mls of Starch and 2 mls of Amylase into each of the four test tubes (make sure you use different syringes)
Place test tube 1 in the ice bath (0ºC)
Test tube 2 at room temperature (20ºC)
Test tube 3 in the 35 ºC water bath
Test tube 4 in 60 ºC water bath
Start the stop clock
Test the samples for starch every 5 minutes

8. Was starch present? Y or N?
Results
Was starch present? Y or N?
0 minutes
5 minutes
10 minutes
15 minutes
20 minutes
A (0ºC)
B (20ºC)
C (35ºC)
D (60ºC)

9. Conclusion
At which temperature did the enzyme work best? How do you know?
How well did the enzyme work at low temperature?
How well did the enzyme work at high temperature?

10. Why does this happen?
Above 45ºC the shape of the active site changes- doesn’t function properly
Above 50 ºC active site altered so much- enzyme doesn’t function at all (LOCK AND KEY)- DENATURED
Low temperature- activity reduced, works v v slowly