AP Biology
Ms. Butler
28 January 2013
I. Title: Effect of a Catalyst on Reaction Rate
II. Introduction: The basis of the experiment is the enzyme; an enzyme is a biological molecule that acts as a highly selective catalyst. By combining with a substrate, an enzyme is able to create a new product that helps the body function. (Ex. Lactose/Lactase) A substrate is a molecule an enzyme acts upon, the two combine at an area called an active site. This active site allows induced fit which allows the reaction to occur and a new product to be formed. In the experiment we utilized the equation: 2 H2O2(aq)-> 2H2O(l) + O2(g).
Through the use of a catalase such as the potato, hydrogen peroxide is broken down to release water and oxygen. Mixtures were allotted time to react, with those have a longer time resulting in more substrate being able to be acted upon in correlation. The sulfuric acid was added after the allotted time and acted as an inhibitor. The inhibitor left a mixture of the products and original hydrogen peroxide. Our titrant of potassium permanganate (KMNO4) shows through its purple color the remnants of the hydrogen peroxide, which we were able to record.
Hypothesis: If we add potassium permanganate to our mixtures then those beakers that were given a longer duration to react will require less titrant because of the little amount of unreacted hydrogen peroxide.
III. Materials:
a. Goggle, Gloves, Protective Clothing
b. Beaker, 150 mL (6)
c. Graduated Cylinder, 10 mL
d. Graduated Cylinder, 100 mL
e. Pipette, 10 mL
f. Pipette (disposable)
g. Burette, 50 mL
h. Funnel
i. Ring Stand
j. Burette Clamp
k. Stop Watch
l. Potato Catalase Enzyme solution
m. Hydrogen Peroxide, 3%
n. Potassium Permanganate, 0.1 M
o. Sulfuric Acid, 0.1 M
p. Water
Procedures:
Label 6 beakers A-F
A. Fill each beaker with 20 mL of hydrogen peroxide leaving beaker A as a control
B. Prepare 2 mL of the catalase to be applied to each of the beakers
C.