Web Lab on Enzymes
1. Go to http://bioweb.wku.eud/courses/Biol114/enzyme/enzyme1.asp
2. Take Cornell Notes on the first page. Click “more” and take Cornell Notes on the
second page.
3. Return to the first page and complete the lab by following the directions on the
screen and answering the following questions.
a. Write the equation for the reaction that the enzyme catalase carries out.
b. Why does raising the temperature increase the rate of the reaction?
c. What can be used to STOP the reaction of catalase? Why does this work?
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d. What is the active site?
e. We start with 3 ml of H2O2 from your bathroom cabinet and add catalase.
After 3 minutes, there is 1ml of H2O2. How much hydrogen peroxide
was consumed.
f. If we repeated the experiment above but found 2 ml of H2O2 remaining,
would this indicate a lower or higher rate of reaction?
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g. Experimental Procedure:
i. ______________ tubes containing catalase and __________ at
different temperatures and examine the rate of enzyme activity by
_____________ any remaining (unreacted) substrate. This will
give use an indirect measure of the substrate converted to
_____________ and therefore the __________ of reaction.
h. When you add H2O2 to the test tubes, do you add substrate or enzyme?
i. The four tubes are placed at what temperatures?
j. After you added catalase, wait 3 minutes and then add what? Why is this
important?
k. What reaction occurred in the test tubes?
l. Titrate, using potassium permaganate, each of the four test tubes and fill
out the chart below.
Tube 1
Tube 2
Tube 3
Tube 4
Amount of
Potassium
Permaganate
needed
Temperature
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m. Which tube had the highest rate of reaction?
n. What variable would have caused the difference in reaction rates for each
tube?
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