Required Practical - Enzymes
Biology: AQA GCSE Higher, topic 2.2.13
Investigating the Effect of pH on Amylase
Amylase breaks down starch, which can be detected using iodine solution.
Measuring reaction time
- Add amylase to starch solution.
- Every 30 seconds, take a drop of the mixture and add a drop of iodine solution.
- Record the total time taken for the iodine solution to stop turning blue when added (which indicates that all the starch has been broken down).
Finding amylase's optimal pH
- Repeat this experiment using starch solutions with different pHs.
- The shorter the time taken for the iodine to stop changing colour, the faster the amylase has broken down the starch and the closer this pH is to amylase's optimal pH.
Test yourself on Required Practical - Enzymes
What are the dependent and independent variables in the experiment investigating the effect of pH on amylase?
Investigating the Effect of pH on Amylase
Using a starch solution with a pH closer to the optimum pH of amylase, how long will it take for the iodine to no longer turn blue when added?
Why does the iodine solution stop turning blue during the amylase experiment?
In the pH and amylase experiment, what does a shorter time for the iodine to stop changing colour tell you?