Required Practical 3: Enzymes

Question 1

Equipment (9)

Answer 1

1. Amylase solution
2. Starch solution
3. Iodine solution
4. Pipettes
5. Syringe/measuring cylinder
6. Cavity tile
7. Timer
8. Solutions of different pH levels
9. Water bath at 40°C

Question 2

Method (10)

Answer 2

1. Put 2 drops of iodine into each well of both cavity tiles.
2. Add 4ml of starch solution to a test tube.
3. Add 2ml of amylase solution into a different test tube.
4. To the tube, add one of the following:
   • 1ml of pH4 buffer
   • 1ml of pH7 buffer
   • 1ml of pH9.2 buffer
5. Put both test tubes into the water bath for 5 minutes to allow them to equilibrate to 40°C.
6. Pour the starch into the test tube with the amylase and start the timer.
7. Every 30 seconds, remove a sample and put one drop into the first space in the cavity tile.
8. Keep doing this until 2 results in a row stay yellow.
9. Repeat with the other solutions
10. Calculate the rate using 1÷ time