The effects of copper ions on the reaction between amylase and starch

Diagram

Apparatus

Dip Tray            - This will allow me to quickly test samples of my solution

Glass Rod          - This will allow me to stir the solution and remove samples

Rinsing Beaker   - This will make sure my main solution is not contaminated

Test Tubes        - This is where the reaction will take place

Potassium Iodide solution  -This will be used to test for starch

Copper sulphate solution   - This is the inhibitor I am investigating

Amylase solution                - This is the enzyme I am investigating

Starch solution                - This is the substance my enzyme will break down

Distilled water                - This is for diluting solutions and rinsing the rod

Stopwatch                - This is to time the reaction so I can calculate the rate

Thermometer                - This is so I can confirm the temperature was constant

Syringes                - These will allow me to accurate measure the solutions

Safety goggles       - These will protect my eyes from the dangerous solutions

Lab Coat                - This will prevent my clothes from being damaged

Method

• Put on safety goggles and lab coat
• Dilute the copper sulphate solution to concentrations of 0.1 M/dm, 0.09 M/dm, 0.08 M/dm, 0.07 M/dm, 0.06 M/dm, 0.05 M/dm, 0.04 M/dm, 0.03 M/dm, 0.02 M/dm, and 0.01 M/dm.
• Add 1 drop of potassium iodide solution to each dimple of dip tray
• Mix the 4cm of the copper sulphate with 3cm of diluted amylase solution in a test tube and note the solution’s temperature.
• Add 2cm of starch solution to the test-tube and begin timing
• Stir the tube’s contents with a glass rod and sample the contents against the dip tray every 10 seconds.
• When the Potassium iodide in the dimple tray is tested and doesn’t change, stop the watch and test again to be sure the iodine wasn’t giving a false impression if no change is observed again, then note the time taken.
• Check there is no temperature change from the beginning and note if there is.
• Repeat the experiment

Variables

PH:  I will control this variable by using only distilled water to dilute my solutions and rinse my glass rod.

Temperature:  I will make sure this variable dose not effect my investigation by performing it at room temperature, I will make sure the amylase breaking down the starch does not effect the temperature, by measuring the temperature of the amylase and copper sulphate solution before and after each experiment.

Concentrations:  I will make sure my concentrations of amylase and starch remain constant by getting my each of my solutions from the same source.  I will also make sure that although the concentration of my inhibitor changes the overall volume of the solution does not.

Stirring:  I will try my best to make sure the amount of stirring is constant throughout the investigation.

Inhibitors:  I will only use one inhibitor for this experiment

Preliminary Results

Volume of Starch        Volume of Amylase        Volume of CuSO        Time        Comment