· 10ml measuring cylinder
· Thermometer
· Stop clock
· Iodine solution
· Starch
· Amylase
· Spotting tile
· Pipettes
· Two test tubes
· Tongs
Method
Firstly, fill the spotting tile indents with iodine (about 5 drops) using a pipette. Then, in two test tubes separately, heat 5ml of amylase solution and 10 ml of starch solution starch. Keep heating over a bunsen burner holding the test tubes with tongs until the temperature of the solutions is 30°C, use a thermometer to be accurate. Once the temperature has been reached mix the two solutions together by pouring the starch solution in with the amylase (swirl the test tube to make sure the solutions mix). As soon as this is done, start a stop watch and every twenty seconds, using a pipette, take some of the mixture and add two drops of it into a different indent on the spotting tile with the iodine each time. The iodine should change colour; this change should be recorded.
Next, the experiment should be repeated but instead of heating the solutions to 30°C, they should be heated to 40° then 50°, 60°, 70°C and lastly 80°C, in order to view the optimum temperature of amylase. All results should be recorded in a table.
Variables
The only thing that differs with each tes is the temperature to which the solutions are heated. It ranges from 30°C to 80°C.
However, the amount of starch (10ml), the amount of amylase (5ml) and the time period for recording (20 seconds) remains the same for all the tests.