amylase practical

Question 1

what does amylase do

Answer 1

breaks starch down into simple sugars

Question 2

method - amylase

Answer 2

1. Get a spotting tile and place one drop of iodine into each well
2. Take 3 test tubes
   - in the first tube, add 2cm3 of starch solution
   - in the second, add 2cm3 of amylase solution
   - in the third, add 2cm3 of a pH 5 buffer solution
3. Place all 3 test tubes in a water bath at 30 degrees for 10 minutes
4. Combine the three solutions into one test tube and stir with a stirring rod
5. Return the solution to the water bath and start a stopwatch
6. After 30 seconds, use the sirring rod to transfer one drop of solution to a well in the spotting tile which contains iodine
7. The tile should go blue black, as starch is present
8. Take a sample every 30 seconds, until iodine stays orange, showing that there is no more starch present
9. Record results and repeat the whole experiment with different pH buffers

Question 3

what is the ph 5 buffer solution used as

Answer 3

to control the pH

Question 4

why do we leave the test tubes in a water bath for 10 minutes

Answer 4

to allow the solutions to reach the correct temperature

Question 5

how can we solve this problem : we are only taking samples every 30 seconds

Answer 5

this means we only have an approximate time to complete the reaction, to address this, we can take samples every 10 seconds

Question 6

how can we solve this problem : we are looking for the time where the iodine does not go blue black, this may not be obvious as the colour change is gradual

Answer 6

ask several people to look at the spotting tile to decide when the reaction has completed