RP-Effect of pH on amylase

Question 1

What is the chemical used to test for the presence of starch?

Answer 1

Iodine solution

Question 2

What are the solutions needed for the effect of pH on amylase practical?

Answer 2

2cm^3 of:

Starch solution
Amylase solution
pH 5-8 buffer solution

Question 3

At what temperature should the test tubes in the water bath be at, and how long for?

Answer 3

30°C for 10mins

Question 4

What do you do with the test tubes of solutions after the time needed has passed?

Answer 4

You need to combine all solutions into one test tube and mix them with a stirring rod, return the tube into the waterbath and start a stopwatch.

Question 5

At what intervals should you drop the solution into the spotting tile?

Answer 5

Every 30s

Question 6

What are the signs that starch is no longer present?

Answer 6

When the iodine remains orange (has no blue-black colour).

Question 7

What do you do once you’ve collected your first set of results?

Answer 7

Repeat the experiment for different pH buffers (preferably 5-8)

Question 8

Problems with the experiment

Answer 8

Samples are only taken every 30s, could be every 10s to get a more accurate time.
It might be difficult to tell when the reaction is finished (it may be hard to find the blue-black colour), so you can try and ask others to see if they see the end of the reaction.