Everything Life Sciences Grade 10

will study the effect of the enzyme catalase on the breakdown of hydrogen peroxide. You

will further examine the effect of pH and temperature on enzyme activity.

Investigation: Investigating the effect of catalase from chicken liver on hydrogen perox-

ide

Aim:

To demonstrate the effect of catalase on hydrogen peroxide

Apparatus:

• 10 ml measuring cylinders


• pipette


• 3% Hydrogen peroxide solution


• scalpel


• forceps


• balance


• chicken liver at room temperature


• boiled chicken liver


• frozen chicken liver


• stirring rod

Method:

Follow the instructions below:

• Cut two square pieces weighing 0.1 g from the fresh liver sample and place each in a
  separate 10 ml measuring cylinder.


• Use a clean measuring cylinder to measure 3 ml water. Pour into one of the fresh
  liver-containing cylinders. This is your negative control.


• Use a clean measuring cylinder to measure 3 ml hydrogen peroxide. Pour into the
  remaining fresh liver-containing cylinder. This is your positive control.


• Wait for four minutes and then measure and record the height of the resulting oxygen
  bubbles in each cylinder.

Questions:

1. Name the three variables that must remain stable throughout these experiments and
   explain why they must be kept stable.


2. What kind of reaction is taking place?


3. How could you make this experiment more accurate?


4. In addition to temperature, what other factors influence the rate of reaction?

46 2.4. Organic compounds