The Science Department
Title: THE EFFECT OF TEMPERATURE ON THE ACTIVITY OF CATALASE
Name:
Grade 7: (A,B,C)
Date: / /2023
Part 1 – The effect of Temp. on the activity of catalase
Materials
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3 clean test-tubes
hydrogen peroxide solution
permeant marker
prepared chicken Liver solution
millimeter ruler
crushed ice
water bath at 70oC
2 Thermometers
Hypothesis
If the temperature increases, then the catalase rate of reaction increase producing more
foam, till it reaches the opt. temp. then the activity will decrease.
Procedure
1. Label tubes 1- 3. Use a permeant marker to draw a line 1cm from the bottom
of each tube. Draw another line at the 2 cm mark.
2. Add yeast solution to the 1 cm line. Note that yeast solution is a controlled
variable in this experiment. Do not add hydrogen peroxide until AFTER step3.
3. Leave the tubes at the following temperatures for 5 minutes
Tube 1 on ice (record the temperature of the ice)
Tube 2 at room temperature (record the temperature)
Tube 3 at 70oC
4. After 5 minutes, add H2O2 (hydrogen peroxide) to the 2 cm line.
5. Measure the height of the foam on each tube using the ruler. Record.
Tube Number
Temperature 0C
Height of foam (mm)
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3.
Results
Prepare a line graph of catalase activity as influenced by temperature.
Analysis
1. Did the results support the hypothesis?
 Answer yes / no depending on your results
2. Identify the dependent, independent variables in the experiment.
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Catalase in different temperatures/ Independent
The amount of foam formed (height in mm)/ Dependent
3. List 2 controlled variables in the experiment.
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The amount of liver solution (amount of catalase)
The concentration of Hydrogen peroxide H2O2
Measure the foam’s height after 5 minutes
4. Evaluate the validity of the method based on the outcome of the investigation.
 If a method measures what it claims to measure, then it can be considered valid.
In this investigation the method was valid as it measured the effect of temperature on the
activity of catalase. I followed each step and made sure that I didn’t miss anything out. I
controlled things like making sure my glassware was clean for each trial. I kept the
temperature monitored during the trials by using a thermometer per each water bath. I
left the liver solution and the hydrogen peroxide in the water for the same time each trial
at each temperature.
5. State improvements or extensions to the method that would benefit the
investigation.
 Are there flaws in the procedures used which could affect the result?
 Were important variables not controlled?
 Are the measurements and observations reliable?
Part 2 - Design an Experiment
Lactaid is a product designed to help people who
cannot digest milk sugar (lactose) because they are missing
the enzyme lactase. Many people are lactose-intolerant, a
condition that is mainly genetic. Lactase breaks down lactose
into two subunits: glucose and galactose.
To test for the presence of monosaccharides and reducing
disaccharide sugars in food, the food sample is dissolved in
water, and a small amount of Benedict's reagent is added.
The solution should progress in the colors of blue (with no
glucose present), green, yellow, orange, red, and then brick red
when there is a large amount of glucose present.
Design an experiment where you would determine how quickly Lactaid works to
break down milk sugar at different temperatures. Be specific in your description,
use drawings if necessary.