Enzyme- Core Practical
Why?
Changes in pH can change how long an enzyme reaction takes. this is because a change in pH can change the shape of the active site.
The effect of pH Amylase can be investigated using starch and iodine.
The Iodine will change colour when mixed with starch but not when the starch has been broken down into sugar.
This is the practical we would do in school, the work will be about a similar practical to the one below.
Method
1. Set up a water bath with a bunsen burner and a beaker.
2. When the water reaches 40oC adjust the bunsen burner to keep the water at this temperature.
3. Place one drop of iodine in each depression in the dimple tile.
4. Measure 2cm3 of amylase solution into a test tube.
5. Add 1cm3 of a pH solution to the tube.
6. Add 2cm3 of starch solution to the tube. Place the tube in the water bath.
7. After 20 seconds take a small amount of mixture and place one drop onto a fresh drop of iodine.
8. Repeat every 20 seconds until the iodine stops changing colour.
9. Record this time in the results table.
10. Record results for other pHs
Info
What to do next...
STILE (Online)
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