Analysis of the Decomposition Rate of Hydrogen Peroxide With Catalase As a Catalyst

Analysis of the Decomposition Rate of Hydrogen Peroxide With Catalase As a Catalyst

Aim: To measure the rate of decomposition of Hydrogen Peroxide with

Catalase from a Yeast solution using PH as a variable.

Hypothesis: The enzyme Catalase speeds up the Hydrogen Peroxide

decomposition as its active sites match the shape of the Hydrogen

Peroxide molecule. This process will only work at certain PH levels as

the Enzyme sites may become disfigured at extremes. Logic suggests

that Catalase will work well at PH7 Neutral, but due to the nature of

Catalase removing Hydrogen Peroxide from human body cells a slightly

acidic solution might work just as well.

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This is based on the Key and Lock principle of the enzyme;

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When various different PH values are present the shape of the Lock of

the Enzyme varies, this can cause a slower rate of reaction, or in the

event of the lock become completely deformed no reaction.

Catalase is present in the peroxisomes of nearly all aerobic cells. It

serves to protect the cell from the toxic effects of hydrogen peroxide

by catalysing its decomposition into molecular oxygen and water.

Catalase

Hydrogen Peroxide---------------------->Water + Oxygen

Catalase

2H2O2------------------->2H2O+O 2

Apparatus Required:

Ÿ Gas Syringe,

Ÿ Metal Stand,

Ÿ Yeast (Catalase),

Ÿ Hydrogen Peroxide,

Ÿ Beakers,

Ÿ Syringe,

Ÿ Stop clock,

Ÿ PH Buffers,

Ÿ Conical flask with Bung including opening for syringe and gas

syringe.

Plan:

Add 5cm3 of yeast into the conical flask, as this gives an easily

measurable volume with little room for error that would occur in

larger volumes, we also only want to measure the decomposition with

the amount of oxygen given off and therefore don't need to notice the

visual changes present in larger experiments. Add 5cm3 of PH buffer

into the conical; flask and mix with Yeast. Insert Syringe filled with

5cm3 of Hydrogen Peroxide into syringe opening, slowly add the H2O2