Background:
Enzymes act as catalysts to help chemical reactions occur. Enzymes lower the activation energy, which speeds up reactions. Enzymes are effected by temperature, ph, and substrate to enzyme concentration. adding heat causes reactions to occur faster. however, adding too much heat will cause the enzymes to denature and lose their function.
Purpose: The purpose of this experiment is to determine the effect of temperature on enzyme function.
Hypothesis: The warm liver will have the best enzyme function because heat means that energy is being added and the reaction will occur faster.
Materials:
- 5 Test Tubes
- 1 Test tube rack
- hydrogen peroxide
- distilled water
- chicken liver
- boiling water
- ice bath
Prepare the contents of the test tubes as outlined below:
a. Test tube 1 - 5 mL water
B. test tube 2 - 5 ml water & liver
c. Test tube 3 - 5 ml water, liver, and hydrogen peroxide
d. test tube 4 - 5 ml water, liver (that has been boiled for several minutes),
hydrogen peroxide
e. test tube 5 - 5 ml water, liver (that has been cooled on ice for several minutes), and hydrogen peroxide
Test one tube at a time
Procedure:
1. Set up test tube
2. add 5 ml of hydrogen peroxide
3. observations
Iv: temperature of the liver
Dv: reaction speed
Control group: test tube 1
Constants: amount of WATER, test tube size, amount of time
Measurement: observation of test tubes
Results:
Test Tube Number
1
2
3
4
5
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Contents
Water
water and liver
water, liver, and hydrogen peroxide
water, heated liver, and hydrogen peroxide
water, cooled liver, and hydrogen peroxide
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Hypothesis
no reaction will occur
no reaction will occur
a reaction will occur
a reaction will occur faster
a reaction will occur slower
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Observation
no reaction
no reaction
fizzing, liver floated to the top
less fizzing, liver did not float to the top
foaming, liver floated to the top faster
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interpretation
there was no reaction for the enzymes to catalyze
there was no reaction for the enzymes to catalyze
The hydrogen peroxide causes a reaction to occur with the liver that is aided by catalase
The heat caused the enzymes to denature and the reaction did not occur as efficiently
this is the optimal temperature for enzyme function because the enzymes denature above this temperature, causing slower reactions
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