How quickly does amylase break down starch when we change the temperature.

Fair Test

I will make sure that I measure the correct amounts of starch and amylase each time. I will always put 3 drops of iodine in each chamber of the spotting tile, no more, no less. I will clean out the test tube and spotting tile thoroughly each time I repeat the experiment. I will always measure the temperature of the water in the beaker accurately with a thermometer.

Equipment List Diagram

* A beaker

* A bottle of starch

* A bottle of amylase

* A bottle of iodine

* A test tube

* 2 spotting tiles

* Kettle

* A pipette

* A syringe

* Stop clock

* Thermometer

Prediction

I predict that the closer the temperature of the starch and amylase gets to 37 degrees Celsius the faster the starch will get broken down by the amylase. I think that as the solution gets higher than that temperature the reaction will either be very quick or very slow depending on whether the reactants become denatured or not. I predict that the line on the graph will go up and then dip if and when the reactant denatures.

Range of results I intend to take

I intend to take results for 20,25,30,35,40,45,50,55,60 degrees Celsius. I will repeat my experiment. I think that there will be a wide range of results because as the temperature of the amylase changes the rate of reaction between the amylase and starch will change. I think there will be anomalous results because I think that at some point the reactants will denature and the reaction will be very slow.

Scientific knowledge to explain your plan and prediction

The amylase works best at around 37 degrees Celsius because that is body temperature. Amylase is mixed in with food in the mouth and as the food passes through the body the amylase reaches 37 degrees and this is the optimum temperature of amylase. Near to 37 degrees the reactant fits snugly into the active site and this means that the starch can be broken down quickly and easily. As the temperature gets higher than 37 degrees the reactant is permanently destroyed and cannot fit into the active site and can therefore not be broken down so the reaction is very slow. If the reactant doesn't become denatured until it reaches a high temperature then the reaction will be very fast. Enzymes don't work at high temperatures. Amylase is a biological catalyst. If there is starch present the iodine will turn blue/black in colour, so when the amylase hasn't broken down the starch the iodine will turn black when the amylase and starch solution is added to the iodine. If the amylase has completely broken down the starch the iodine does not change colour when the amylase and starch solution is added to it.

Diagrams to illustrate detailed science

Explain how you will make sure your results are precise and reliable

I will make sure my results are precise and reliable by recording my results accurately. I will make sure that the spotting tile and the test tubes are cleaned thoroughly after each experiment. I shall measure the temperature accurately and use the same equipment throughout the course of the experiments. I will make sure I am not biased when judging when the starch has been broken down. I shall repeat the experiment to ensure the results give a more precise indication of the reaction rate between amylase and starch. I will use a syringe instead of a measuring cylinder because this means that the measurements are much more reliable and accurate. I will use a thermometer which can measure temperature precisely.