Effect of pH on amylase

What do you do with Iodine solution?

Place one drop of iodine solution into each well of a spotting tile

What do you put into the 3 test tubes?

1. 2cm³ Starch solution

2. 2cm³ Amylase solution

3. 2cm³ pH 5 buffer solution

What do you then do with the 3 test tubes?

Place them in a hot water bath at 30 degrees Celsius for 10 minutes

What do you then do with the contents of the 3 test tubes?

Combine them in one test tube and mix with a stirring rod, then place in the water bath, as well as starting a stopwatch

What do you do every 30 seconds after?

Place a sample into a well full of iodine

When do you stop and why?

When the iodine stays orange as this means the reaction has completed

What do you record?

The time taken for the reaction to complete

What do you do to investigate how different pH solutions affect amylase?

Repeat the experiment with different pH buffer solutions, e.g. 6, 7,and 8

What are problems with the experiment and how can we solve them?

1. We record every 30 seconds, so we only get an approximate time. We can solve this by recording every 10 seconds

2. The time when the iodine changes colour is not obvious, as the colour change is gradual We can solve this by getting several opinions on when the reaction has completed