Abstract: In this experiment we observed the effects of pH and temperatures on catalyse activity
(chicken liver) depending on if they are in a “poisonous chemical.” We dropped the chicken liver
in the HCl (acid), diluted HCl, NaOH (base), diluted NaOH, and water. We also boiled a piece of
chicken liver to determine the effect on enzymes in the chicken liver. We determined if the
enzymes in the liver protected the liver from breaking down.
Introduction: In this lab report, we determine the effects of pH and temperatures on catalyse
activity in chicken live, as well as see if other types of tissues have Catalyse Enzymes in them.
My group and I hypothesized that if the temperature became too high then the reaction rate will
go down. We also hypothesized that a high pH would speed up the reaction, and a low pH would
slow the reaction.
Methods: In the pH part of the experiment we filled 5 test tubes. In the first test tube we put 3
drops of HCl (acid). In the second test tube we put 1 drop of water for every 3 drops of HCl. In
the third test tube we put 3 drops of NaOH (base). In the fourth test tube we put 1 drop of water
for every 3 drops of NaOH. Finally, for the fifth test tube we put 3 drops of water. In each of
those test tubes we put in a piece of chicken liver to test if the enzymes in the liver reacted to the
liquid. In the temperature part of the experiments we boiled a piece of chicken liver to determine
if the drastic temperature change killed the enzymes. We then let the test tube cool, poured the
water and replaced it with hydrogen peroxide to see the effects on the chicken liver without
enzymes. Then we put equal quantities of liver into 2 clean test tubes and 1 ml H2O2 into 2 other
test tubes. Then we put one test tube of liver and one of H2O2 into each of the following water
baths: ice bath and warm water bath (not boiling). We observed the results. After 3 minutes, we
poured each tube of H2O2 into the corresponding tube of liver and observe the reaction.
Results: From the first part of the experiment, which was only the observation of the liver going
into the 2H2O, showed the 2H2O fizz (produce oxygen and water) once the liver was dropped
into it. With the second part of the experiment, which tested what tissues have Enzymes in it,
resulted with all tissues having Enzymes in it. The third part of the experiment tested how
temperature affected Catalase. Boiling water, well heat in general, effected the rate of Catalase
from 4-5, to 0-1. The heat killed Enzymes that were stabilized and kept active by refrigeration.
The last part of the experiment was testing how pH affects Catalase activity. There were 5 test
tubes with H2O2 in them, as well as add-ons of, HCL, HCL and water, water only, NaOH with
water, and NaOH with water as well. The NaOH, which is a strong base, turned out to have the
highest reaction rating, whereas, the HCL had the lowest reaction rate. Given the data of the last
part of the lab, it is safe to conclude that the ideal pH for Catalase activity is around 11.
Discussion: In this lab, there weren’t many controversial points between the group. In the first
phase of the experiment, everyone agreed that it made sense how the Enzymes broke down the
Hydrogen Peroxide by producing water and oxygen when reacting. In the second phase,
everyone was in an agreement that the chicken liver would react, but we were split between
whether or not the other two would or not. After we experimented, we realized that all tissues
probably have Catalase Enzymes in them. Before beginning the third part of the Lab, we
realized that it said in the introduction how dead tissue can be used because if its refrigerated
then the Enzymes stay active. So, before starting Part three we had already hypothesized that the
heat would kill the Enzymes. Our hypothesis proved correct because the reaction barley, if not
didn’t, take place after the chicken liver was boiled. With the last part of the experiment, we
hypothesized that, since Hydrogen Peroxide is barley acidic and reacts well, that the more acidic
would react even more. However, after the experiment took place, we realized that the more
basic tended to produce better Catalase activity than the Acidic.
Conclusion: My group and I concluded from the lab experiment that Catalase is contained in all
types of tissue if kept active by cold. Also, given that all tissues reacted in the Hydrogen
Peroxide, we have come to the conclusion that all tissues contained Catalase, but not the same
amount. We concluded that the faster the reaction, the more Enzymes, thus the more Catalase
activity. The Apple had the least, the Potato had the median amount, and the Chicken liver had
the most. After, during our next experimentation with temperature, we concluded that heat kills
Enzymes. We came to this conclusion because in the experiment, when the liver was put into
H2O2, after being boiled, its reaction rate was 0-1, whereas its rate was around 4-5 refrigerated.
Lastly, we experimented with pH levels, and their effect on Catalase activity. We came to the
conclusion that the more basic solutions increase Catalase activity, and the more acidic solutions
significantly decreased the Catalase activity. Also, given the data of the last part of the lab, it is
safe to conclude that the ideal pH for Catalase activity is around 11. To some up the experiment,
Catalase activity is effected in many different ways, by many different factors, and also, can be
contained in many different tissues.