1. TED ANKARA COLLEGE FOUNDATION HIGH SCHOOL
EXPERIMENTAL DESIGN
Prepared to: Hatice ÖZMEN
Prepared by: İrem ERK
Due date: 14.10.2011

2. REASEARCH QUESTION:How does the reaction rate changes in a reaction in
which catalyze enzyme reacts with hydrogen peroxide (H2O2) when amount of
H2O2 is increased 200 ml to 400 ml.
MATERIALS:
1) tubes
2) chopped liver
3) H2O2
HYPOTHESIS:
 The reaction, which has 400 ml H2O2 occurs faster than the other
reactions.
VARIABLES:
Independent Variables: reaction rate
Dependent Variables: time
Controlled Variables: Type of enzyme
Pressure
Type of substrate
Size of tube
Amount of enzyme
Amount of substrate
STRUCTURE OF EXPERIMENT:
Same amount of chopped liver is put into the tubes. First, 200 ml H2O2 is added
to first tube and reaction rate is measured. Then, 400 ml H2O2 is added to the
other tube and its reaction rate is measured too.
CONTROL OF VARIABLES:
Enzymes: are proteins that catalyzechemical reactions. In enzymatic reactions,
the molecules at the beginning of the process, called substrates, are converted
into different molecules, called products.
Catalase: is a common enzyme found in nearly all living organisms that are
exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide
to water and oxygen.

3. Hydrogen peroxide(H2O2): is the simplest peroxide (a compound with an
oxygen-oxygen) and an oxidizer. Hydrogen peroxide is a clear liquid, slightly
more viscous than water. In dilute solution it appears colorless. The oxidizing
capacity of hydrogen peroxide is strong.
In this experiment, in which hydrogen peroxide and catalase react, the
rate of the reaction is evaluated. Because of the thing, which is measured, is rate
of the reaction, the reaction rate is the independent variable for this experiment.
On the other hand, the dependent variable is time. Because time, changes
with the rate of the reaction. In other words, time depends on reaction rate for
this experiment.
Finally, controlled variables are pressure, size of tubes, type of substrate,
amount of enzyme, amount of substrate and type of enzyme. These are constant
along the experiment, because, the thing that is measured is the rate of reaction.
If one of the constant variables is changed, the experiment changes. So, observer
cannot find the result what he expects to find. For example, if amount of enzymes
would different in each measurement, the observer would measure how amount
of enzyme affects the reaction.
DATAS:
 Time
 Pressure
 Amount of substrate
 Amount of product
amount of substances (ml)
200.00 400.00
pressure(atm) 22.40 22.40
time(second) 60.28 120.37
As amount of substances increases reaction rate becomes slower.