ENZYMES AND THE EFFECT OF TEMPERATURE ON ENZYME ACTIVITY In this lab you will pe
ID: 81151 • Letter: E
Question
ENZYMES AND THE EFFECT OF TEMPERATURE ON ENZYME ACTIVITY
In this lab you will perform an experiment that demonstrates the function of enzymes and some factors that influence the activity of enzymes. In the experiment, the enzyme to be tested will come from potatoes.
Enzymes are important to the digestion of food. They act as a catalyst to speed up the reaction of food being broken down. Without enzymes to catalyze the digestive processes, food would pass out of our bodies before it could be absorbed into our blood stream. In this experiment we will see the effect of a catalyst on a chemical reaction.
Catalase is an enzyme present in many living things. This enzyme catalyzes the breakdown of hydrogen peroxide to water and oxygen. As the oxygen gas forms, bubbles will appear. The chemical reaction is given below:
2H2O2 > 2H2O + O2
What is the “Substrate” in this chemical reaction?
What is the enzyme?
What are the end products?
Materials Needed
Potato
Knife
Eye Dropper
Boiling Water
4 Saucers
Hydrogen Peroxide (From the Drug Store)
Procedure
Cut a potato into thin slices, about one inch squares. You will need four slices.
Put two pieces of the potato into boiling water for five minutes.
Prepare four dishes of room temperature tap water. Label them A, B, C, and D. Put the potato slices into the dishes as follows; A=fresh slice, B=boiled slice, C=fresh slice and D=boiled slice.
Into dishes C and D, add 30 drops of hydrogen peroxide.
Record your observations regarding bubbling for A, B, C, and D.
Explain why bubbling occurred or did not occur in each dish.
In each dish that did not bubble, what do you think was missing?
In each dish that had bubbling, what was present that allowed for the bubbling to take place?
What do you think might happen if the fresh potato slice was put into ice water before the hydrogen peroxide was added? Explain your answer.
Explanation / Answer
In this chemical reaction, the substrate is hydrogen peroxide.
The enzyme is catalase.
The end products are water and oxygen gas.
Dish A and B no bubbles. The dish C showed most bubbling and the dish D produced little to no bubbles.
The dish C showed most bubbling as catalase works best at a room temperature. The dish D produced little to no bubbles as the heat degraded the catalase enzyme, making it incapable of processing the hydrogen peroxide. In dish A and B there occured no bubbling since hydrogen peroxide was not added to it.
In dishes A and B that didnot bubble, there was missing hydrogen peroxide with whom the catalase enzyme would habe been reacted to produce bubbles.
In dishes C and D, presence of hydrogen peroxide allowed for the bubbling to take place. Catalase takes the role of a catalyzing enzyme in the decomposition of hydrogen peroxide. Nearly all living things possess catalase which helps in the decomposition of one substance into another. Catalase decomposes hydrogen peroxide into water and oxygen.
If the fresh potato slice was put into ice water before addition of hydrogen peroxide, it may have produced fewer bubbles than the room temperature sample with tap water as the cold temperature slowed the catalase enzyme’s ability to decompose the hydrogen peroxide.
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