G9 Biology ws 4.1

1

Q: What is the purpose of setting up test tube E?

A: It is a control to show that no oxygen is given off from hydrogen peroxide solution without tissue.

2

Q: What does the relighting of a glowing splint indicate?

A: The gas given off is exygen.

3

(+) oitati, apple, liver, meat

(-) no tissue added

4

Q: What do the results of this practical tell us?

A: Tissues of potatoes, apple, liver and meat catalyse the breakdown of hydrogen peroxide to oxygen.

5

Q: This practical does not show the breaking down of catalase directly. What can be done further to show that the breakdown of hydrogen peroxide is catalysed by an enzyme?

A: Boiled tissues, instead of fresh tissues, can be used in a further investigation. If the boiled tissues have no catalytic action, it is more likely that the reaction is catalysed by an enzyme.

6

Q: What conclusion can you draw from this practical?

A: The breakdown of hydrogen peroxide is catalysed by tissues, probably by an enzyme in the tissues.