1. Investigations with phosphatase Paul Beaumont Science & Plants for Schools Homerton College, Cambridge

2. OCR specification 5.1.3 Enzymes – Learning Outcomes: (c) describe and explain the effects of pH, temperature, enzyme concentration and substrate concentration on enzyme action. (d) follow the time course of an enzyme-catalysed reaction by measuring rates of formation of products or rate of disappearance of substrate (e) explain the effects of reversible inhibitors (both competitive and non-competitive) on the rate of enzyme activity. 5.1 Module 2801: Biology Foundation

3. Phosphatase Phosphatase enzymes from plants: a versatile resource for post-16 courses Meatyard, B. (1999), J. Biol. Educ., 33(2), 109-112.

4. Phosphatases Found in wide range of plant and animal tissues Release phosphate groups Phosphate available for ATP and nucleotide synthesis, membrane construction. Two main groups – acid and alkaline

5. The Assay

6. Experimental Outline Preparing a standard curve (Part A) Preparing the enzyme extract (Part B) Running the assay (Part C)

7. PPP = phenolphthalein phosphate (substrate) PP = phenolphthalein (product)

8. Kit contents

9. Additional materials

10. Standard curve Solution Number Volume of PP stock, (cm 3 ) Volume water, (cm 3 ) Volume Na 2 CO 3 (cm 3 ) PP concentration (mol dm -3 ) 1055.00.0 21.04.05.05.0 x 10 -6 32.03.05.01.0 x 10 -5 43.02.05.01.5 x 10 -5 54.01.05.02.0 x 10 -5 65.00.05.02.5 x 10 -5

11. Colorimeter R = ReferenceT = Test Direction of Beam

12. Standard curve

13. Germination

14. Creating the extract

15. Maceration

16. Loading centrifuge tube

17. Centrifugation

18. Retain supernatant

19. Running the Assay

20. Running the assay

21. Results

22. Results

23. Phosphatase Investigations Phosphatase Investigations Effect of temperature Effect of pH Phosphatase levels from different species Phosphatase levels in different locations Effect of phosphate concentration