In our biology class, we started studying enzymes. In order to see how the Catalase works, our teacher told us to do an experiment.
AIM: how temperature affects the activity of catalase.
This was the task:
1- Write down the equation of the chemical reaction in words and build a table to record your results.
2- The teacher provides you with:
a- 3 test tubes filled with hydrogen peroxide (substrate)
b- a piece of potato (source of catalase)
3- Cut the potato into 2 cubes of 0.5 cubic centimeters each. The third cube has already been prepared for you.
4- Place one cube and one test tube in the 1st water bath at 5°C for 2 minutes.
5- Place the cube into the test tube and leave it in the water bath for 2 minutes.
6- Measure the height of the foam produced.
7- Record the result in the table.
8- Repeat steps 4 to 7 with the other cubes.
9- Plot the information in a line-graph
a- Why did you leave the potato and the test tube in the water baths before the experiment?
b- State: – the independent variable
The temperature.
– the dependent variable
The height of the foam produced.
– two fixed variables
c- Describe the results shown in the graph.
d- At what temperature the enzyme works best?
At 30ºC.
e- What has happened at 100°C?
No foam is produced. There is no activity because at high temperatures the active site loses its shape, therefore the substrate doesn’t fit into the enzyme. The enzyme is denatured.
