How Different Concentrations of Hydrogen Peroxide Would Affect the Activity of Catalase

Only available on StudyMode
  • Download(s) : 477
  • Published : May 22, 2012
Open Document
Text Preview
How different concentrations of hydrogen peroxide would affect the activity of catalase? 1. Variables

IndependentConcentration of hydrogen peroxide
DependentVolume of oxygen gas evolved
ControlAmount of liver used
Location of liver sample obtained from the liver
Type of liver used
Possible enzymes transferred from hands during making liver homogenate Deterioration of liver
Endpoint identification
Volume of hydrogen peroxide added
Reading on the syringe
Room temperature

2. Hypothesis
The research question examines how different temperatures would affect the activity of catalase. In order to carry out the investigation, amount of oxygen produced is measured through the apparatus for each temperature. Hydrogen peroxide is a toxic by-product of metabolism in organism. Thereby it must be quickly degraded or converted. The enzyme catalase catalyses the conversion of hydrogen peroxide into water and oxygen, which are none toxic to organisms. The range of optimum temperatures for animal catalase is between 37oC – 40oC. Therefore the liver homogenate will be stored at 38oC to maintain its maximum activity throughout the experiment. However substrate concentration is one of factors that affect the rate of enzyme activity. Since the enzyme catalase breaks down hydrogen peroxide into oxygen and water, measuring the volume of oxygen gas evolved would indicated the rate of catalase activity. With an increasing concentration of hydrogen peroxide, the volume of gas collected would increasing as there are more substrates for catalase to break down as the study by P. George indicates that the rate of reaction is ‘found to be directly proportional to the enzyme concentration’. But as the study by Evans CA Lovatt suggests ‘above an optimum concentration as the peroxide is increased the reaction proceeds more slowly.’ Thus the data would show diminishing returns in the end as the enzyme would be saturated with an excessive concentration of hydrogen peroxide; hence it would produce relatively consistent volume of gas at higher substrate concentration.

3. Apparatus list
100ml beaker (7)
250ml beaker (1)
500ml beaker (2)
2M hydrogen peroxide (500cm3)
100cm3 Measuring cylinder ±0.5cm3 (3)
Measuring pipette 1cm3
Boiling tube (25)
Boiling tube rack (1)
Distilled water (5 bottles)
Thermometer ±0.5oC (0-100oC)
Clamp/clamp stand
Blender
Pig liver
Two hole rubber stopper (3)
10cm3 Measuring cylinder ±0.05cm3 (1)
Transparent plastic wash pan (2)
Vertical glass tube
J shaped glass delivery tube
rt angle glass delivery tube
30-40cm length rubber tubing
5cm length rubber tubing
Stopwatch ±1.0sec (2)
Latex rubber glove
6cm3 syringe±0.05cm3
1cm3 syringe±0.005cm3
25cm3 syringe±0.5cm3

4. Method
Dilution method for hydrogen peroxide
0.4M Hydrogen peroxide solution
Add 2cm3 of 2M hydrogen peroxide into 100cm3 beaker using 6cm3 syringe Read the syringe from the line at the end of the plunger
Add 8cm3 of distilled water into 100cm3 beaker using 10cm3 measuring cylinder Label the beaker as 0.4M hydrogen peroxide
0.8M Hydrogen peroxide solution
Add 4cm3 of 2M hydrogen peroxide into 100cm3 beaker using 6cm3 syringe Read the syringe from the line at the end of the plunger
Add 6cm3 of distilled water into 100cm3 beaker using 6cm3 syringe Label the beaker as 0.8M hydrogen peroxide
1.2M Hydrogen peroxide solution
Add 6cm3 of 2M hydrogen peroxide into 100cm3 beaker using 6cm3 syringe Read the syringe from the line at the end of the plunger
Add 4cm3 of distilled water into 100cm3 beaker using 6cm3 syringe Label the beaker as 1.2M hydrogen peroxide
1.6M Hydrogen peroxide solution
Add 8cm3 of 2M hydrogen peroxide into 100cm3 beaker using 10cm3 measuring cylinder Add 2cm3 of distilled water into 100cm3 beaker using 6cm3 syringe Read the syringe from the line at the end of the plunger

Procedure
Place a thermometer in the centre of the experiment location, monitor and record the room temperature...
tracking img