How Does Temperature Affect the Action of Amylase On Starch?

Plan

After performing a number of pilot experiments I decided that the best ratio of Starch Solution (1%) to Amylase Solution (0.5%) was 1:3 (1 part Starch solution to 3 parts Amylase solution). I then therefore decided to use 2ml of Starch Solution and 6ml of amylase solution. I also decided to take samples every 30seconds because I discovered that anything above that gave a reading that was too vague and anything below was too frequent and therefore difficult to take the samples at the correct times.

Apparatus

I will use different apparatus for the experiments that are performed at different temperatures but here is a full list of the apparatus:

* Stop Clock, Water Bath, Gauze, Bunsen Burner, Tripod, Large beaker's, Large beaker's, Pipette, Thermometer's, Test Tube's, Cavity Tile, Syringe, Water Bath's,

Plan

I will perform experiments at the following temperatures:

. Freezing (0(c)C)

2. Room Temperature (about 20(c)C)

3. 40(c)C

4. 80(c)C

5. Boiling (100(c)C)

I will now take you through how I will perform each of the five experiments with each experiment you will need to take a cavity tile and place one drop of iodine in each cavity on the tile.

. Using a syringe measure out 2ml of starch solution and 6ml of amylase solution place them in separate test tubes and leave to chill in a large beaker containing crushed ice. Add a thermometer to each test tube, and when the temperature reaches 0(c)C add the amylase to the starch and immediately start the Stop Clock and take the first sample (which consists of using a pipette to place one drop of the solution into one of the cavity's). Continue to take samples every 30 seconds up to and including 600seconds (it would be impractical to go any higher because of the limited amount of time that we have) or until when tested it was discovered that no starch was present. You can tell there is no starch present by testing with Iodine (if starch is present the solution will turn black.

2. Repeat '1.' But instead of using a beaker containing ice, leave the Starch and amylase to stand before mixing together

3. As before but place the starch and amylase in a water bath set at 40(c)C and leave until the temperature is reached

4. Repeat '3' but set the water bath at 80(c)C instead of 40(c)C

5. Set up the apparatus as shown:

Once the Water in the beaker is boiling place the two separate Test tubes in, once the temperature reaches 100(c)C add the Starch and Amylase solution to each other and take samples in the same way as the previous experiments

Fair testing

.

You should take the following measures to ensure fair testing:

* Clean the pipette after each sample

* Check each measurement twice

* Start the timer straight away (when the amylase and starch mix)

* Check all apparatus for contamination before

* Check the starch and amylase are at the correct temperature before the experiment is started

* Check the syringes for air bubbles, so you can be sure you have an accurate reading

* Each section will be repeated to ensure the reading is fair

Observations

Temperature of amylase and Starch

Time that all starch was broken down (Seconds)

0(c)

600*, 600*

Room Temperature (about 20(c)C)

540, 510

40(c)C

270,270

80(c)C

30,60

00(c)C

600*, 600*

* = After 600 seconds there was no result

I then noticed that some values had varied to take this into account I will take an mean average from both the values giving the following table as my final results

Temperature of amylase and Starch

Time that all starch was broken down (Seconds)

0(c)

600*

Room Temperature (about 20(c)C)

525

40(c)C

270

80(c)C

45

00(c)C

600*

Sam Page 1 02/05/2007