1. Lesson Starter What are enzymes made out of?
Why did the enzymes work best at 35°C?
Explain what happens to the enzymes active site about 50°C and the effect this has on enzyme activity

2. Enzymes

3. To learn about the affect of pH on enzymes
Learning Intention
To learn about the affect of pH on enzymes

4. What we know so far.. Enzymes are made of protein
They have a SPECIFIC shape- complimentary substrate
Too cold- enzymes work v slowly
Too warm- active site loses shape- DENATURED
Working range- enzyme is active
Optimum- PERFECT!

5. Enzymes and pH Enzymes have an OPTIMUM pH
Cells in our body have pH of 7- most enzymes OPTIMUM pH

6. What do you think the optimum temperature of pepsin would be?
Involved in digestion of protein
Found in stomach
Human stomach ACIDIC
What do you think the optimum temperature of pepsin would be?

7. Pepsin works best between pH 2 and 3
Involved in digestion of protein
Found in stomach
Human stomach ACIDIC
Pepsin works best between pH 2 and 3

8. What does this tell you about the optimum conditions for catalase?
Working range between pH 7 and 11
Optimum pH is around pH 9
What does this tell you about the optimum conditions for catalase?

9. Catalase works best in ALKALINE conditions
Working range between pH 7 and 11
Optimum pH is around pH 9
Catalase works best in ALKALINE conditions

10. Every day uses of enzymes

11. Biological Washing Powders
Contain enzymes (from bacteria)
Digest the large molecules that make stains- can be washed away
Different enzymes for different things

12. Experiment: Aim
To demonstrate the effectiveness of biological and non-biological detergents at different temperatures

13. Apparatus 4 test tubes Test tube rack 4 pieces of (stained) fabric
2 x 10 ml syringes
Whole class shared
Water 70°C
Water 40°C
Biological detergent
Non-Bio detergent

14. Method Label the test tubes A, B C, D
Place 5 mls of water in each of the test tubes
Into test tubes A and B add a spatula full of BIOLOGICAL detergent
Into test tubes C and D add a spatula full of NON-BIOLOGICAL detergent
Place A and C into the water bath at 40 °C
Place B and D into the waterbath at 70°C
Leave for 30 minutes

15. Biological enzymes
Biological washing powders contain enzymes to help to remove stains from clothes
Different stains are removed by different types of enzymes

16. Biological washing powders
Fat stains- butter
What type of enzyme would digest a fat stain?
Lipase- fat-only digesting enzymes

17. Biological washing powders
Starch stains- grass
What type of enzyme would digest a grass stain?
Amylase- starch digesting enzyme

18. Biological washing powders
Protein stains- blood
What type of enzyme would digest a grass stain?
Protease (pepsin/trypsin)

19. Method- In your own words
Write the method for setting up the experiment for someone else to follow
Include an apparatus list, step by step instructions and diagrams

20. What do you think will happen in each test tube and why?
Hypothesis
What do you think will happen in each test tube and why?

21. Results Which detergent worked best at 40°C? Why?

22. Conclusion SAVES ENERGY
Biological detergents (containing enzymes) work best at low temperatures- OPTIMUM
Non-bio detergents work best at high temperatures
What would the big benefit be of using a biological detergent?
SAVES ENERGY