Enzymes are biological catalysts made of proteins that speed up chemical reactions without being consumed. This experiment tested how different substances—raw potato, boiled egg white, boiled potato, and yeast—affected the rate of reaction between catalase enzymes and hydrogen peroxide. Raw potato and yeast produced the most froth, indicating the fastest reactions, because their active enzymes were not destroyed by boiling. Boiled potato showed no reaction since boiling degraded its enzymes. Boiled egg white reacted more slowly than raw potato due to changes in pH from boiling.

1. ENZYMES
• BY:
• HOLLY ERIN WHITE
• JORGE GOITIA
• REEM ALAZHRI
• ZAYNAB YAHYA GORKI

2. What are Enzymes?
• Enzymes are biological catalysts made of
protein.

3. What are Catalyst?
• A catalyst is a substance, which can alter or speed
up a chemical reaction, without itself being
chemically changed at the end of the reaction.
•

4. • Digestion is an enzyme-catalyzed process. Some food molecules are large
and insoluble in water; these molecules cannot diffuse through the cell
surface membrane. Imagine a meal consisting of fish and rice:
• Rice contains starch, a very large carbohydrate molecule.
• Fish contain two types of large molecules: protein and fats.
What reaction do Enzyme
Catalyze?

5. •EXPERIMENT
The effect of Catalase on
Hydrogen Peroxide.

6. • Catalase is an enzyme found in many plant and animal
tissues. The enzyme has the function of breaking down
dangerous peroxide ions. As it does, oxygen gas is released
–because the reaction is rapid, the oxygen bubbles form
froth on the top of a reacting solution.
INTRODUCTION!

7. • 1. The temperature of the surroundings and test tubes
• 2. The pH value of its surroundings
• 3. The substrate volume
• 4. Mass of enzyme used
In the experiment the key factors that could affect the
results o
f the
Experiment will be:

8. • To determine the effect of catalase on hydrogen peroxide.
• To conduct the experiment correctly.
• To gather appropriate data for analysis and conclusion.
OBJECTIVES:

9. • Hydrogen peroxide
• Test tubes
• Potatoes
• Egg white
• Yeast
• Wooden splint
• Graduated cylinder
• Knife
• Chopping board
• Beaker
• String spoon
MATERIALS:

10. PROCEUDRE:
• Gather all the needing materials.
• Peal one potato and cut it in small pieces, get the beaker and pour the
cutting potatoes into, then boil it.
• Peal one potato again and cut it in small pieces.
• Break your egg white and pour it into the beaker
• Measure 10ml of hydrogen peroxide into each test tube or boiling tubes.
• Label each test tube A, B, C, D.
• To each test tube, add one of the following substances: A. some chopped
raw potato, B. egg white, C. some chopped boiled potato, D. some yeast.
• Place each test tube in the test tube keeper.
• Gently observed the experiment
• Record your observation, and explain them as fully as you can.

11. A. Raw potato: we think that the enzyme will react greater with the potato and produce
More froth when it is cut up.
This is because as you cut it up into smaller bits, you make the
Surface area greater meaning there are more enzymes to react with each
Other, and there will be more successful collisions between the two
Reactants.
B. Boiled egg white: when the egg was drop in hydrogen the ph value increase that is why it produced a lot of
bubble and the enzyme speed up faster.
C. Boiled potato: during the process of boiled potato there was no reaction or bubble this was due to the lack of
Enzymes that was already burn when boiling.
E. Yeast: This is always happening but at a very low rate so you don't notice it. If you add yeast to hydrogen
peroxide it will speed up the decomposition of H2O2. However the yeast does not react with the H2O2 and
nothing is chemically altered in the yeast. That is because yeast is a catalyst.
ANALYSIS AND INTERPRETATION
OF DATA:

12. TUBE CONTENT HIEHT OF FROTH IN
ONE MINUTE(CM)
A RAW POTATOES 9.8CM
B BOILED EGG WHITE 1CM
C BOILED POTATOES NOTHING
D YEAST 9CM
DATA:

13. A. Raw Potatoes :the raw potatoes produced many bubble and the enzymes
speed up faster.
B. Boiled Egg White: The boiled egg white actually have bubble but the
speed of the enzymes was quite slow this is because of the PH value .
C. Boiled Potatoes: The boiled egg has not reaction or produced anything
this is because the enzymes are already broken down.
D. Yeast: The yeast reaction to the hydrogen peroxide has a greater
decomposition but a very low rate. Many bubble present.
OBSERVATION:

14. •
CONCLUSION: how enzymes
With todays experiment we quite learn and observed
factors affect different substances. And we do hope that this lesson
will never skip out of our memories.