P5 Biochemistry For any 2 of the 3 enzyme experiments that you performed: Describe how the experimental results were obtained (method), Provide a suitable table and graph for your results, ⦁ Explain what each graph shows regarding enzyme activity.

Hi guys,

Heres another to enjoy,

The first experiment was to show how the temperature affects the activity of the amylase. The method in which we used to gain these results is:

• Measure the room temperature with a new thermometer and use a pen to name the beakers 1 and 2. Divide 10 test tubes into 2 groups and name then 1-5 in each group. Stopwatches are required to record the time in which the blue/black colour disappears.

•  Crushed ice is then added to beaker 1 and I must be filled with tape water. Beaker 2 is filled up with tap water. A thermometer is placed in each beaker and we left it for a few minutes. Once the temperatures reached the reaction temperature the experiment begins. 3cm³ of amylase must be added into a 10cm³ measuring cylinder, add more drops or pour away drops until it reaches the 3cm³ marks and then pour the solution into beakers 1-5. Repeat the step to the starch solutions and pour then into beakers 1-5 in the second group. 
•  Test tubes 1 from each group must be put into beaker 1. Test tubes 2 from both groups must be put into a water bath of 40°C. 
• The temperature of each of the solutions must be checked every 30 seconds using thermometers to determine the current temperatures of the solution. 
•  If the two types of solution in one container have already reached the reaction temperature, then up and start the corresponding stopwatch as fast as you can. Add a drop of iodine solution immediately into the mixture of amylase solution and starch solution. 
•  The colour then must be checked. When the blue/black colour disappears then the time must be recorded.

At this point add a table to show the results of the experiment on how temperature effects the activity of amylase.

For e.g. 

c         Time in minutes

20°C 9

30°C 6

40°C 5

45°C 4

50°C 2

55°C 7

The technique to test how the concentration of hydrogen peroxide affects the rate of the reaction is as follows:

⦁ Add 2cm³ of yeast into one test tube and in another test tube, add 4cm³ of hydrogen peroxide solution at a concentration of 20% into the other tube. A pipette is used in order to measure the volumes. It’s important to note that the measurements are accurate to ensure a fair test. 

⦁ The hydrogen peroxide solution is then poured into the test tube which contains the yeast. Then the gas syringe stopper is put at the end of the test tube and the stopwatch is then started. 

⦁ The experiment bubbles at this point will then rise up the tube and the gas syringe will move outwards. When this passes the 30cm³ marks, the stopwatch must be stopped and the time must be recorded. 

⦁ The test must be recorded at least three times so an average is obtained. Once the time is taken is found, the rate can be worked out by using this formula: rate= 1000/time in secs.

You now might want to add a table to show the effect of substrate concentration on enzyme activity (catalase)

% Hydrogen Peroxide Time in secs Rate

10%                          286                  3.5

20%                                 182                  5.5

30%                                 160                  6.3

40%                                 139                  7.2

50%                                 130                  7.7

60%                                 120                  8.3

70%                                 110                  9.1

80%                                 100                  10

90%                                 104                  9.6

100%                         96                  10.4

Anything you wanna see here just ask!!

All comments welcome. 

Your study pal

xo