Action of amylase on starch Number 2

Conditions needed for the action of amylase
It is essential to check effectiveness of amylase/starch mixture before the experiment; concentrations of amylase (&starch) could be halved/doubled to bring conversion time to a reasonable value
Standard treatment (2.0 ml amylase, temperature 36° C, no pH additions, 10ml starch) should show starch is not present after about 6 minutes.

Outline:

Experiment 1: Variations in amount of amylase
Experiment 2:Variations in Temperature
Experient 3: Variations in pH
Experiment 4: Variations in amount of starch (optional)

Put amylase in water baths/ice before lesson starts

Apparatus

1 and 3 cm3 pipettes
10cm3 measuring cylinders
Plastic rods
Spotting tiles
pH papers - narrow range (expt 3 only)
Universal indicator paper (expt 3 only)
Iodine in KI
Ice
Water baths:2 x 36ēC; 54ēC; 72ēC

Materials

1.5% Amylase
1.0% Starch
Totals depend on number in class/number of groups per experiment.

EXPT AMYLASE STARCH
1 20cm3 in 1 tube in 36ēC water bath 75cm3
2 2cm3 in separate labelled tubes for each temperature 75cm3
3 20cm3 in 1 tube in 36ēC water bath 75cm3
4 20cm3 in 1 tube in 36ēC water bath 100cm3