A Strawberry Sundae - not even delicious looking

Demonstration Experiment on Video

A Strawberry Sundae - not even delicious looking

Objective: Enzymatic Decomposition of Hydrogen Peroxide

Peter Keusch

German version

Chemicals and other substances:
hydrogen peroxide 30 %

blood

Glass wares:
conical measure 300 mL
2 beakers 50 mL
2 volumetric pipettes 10 mL
2 pipette bulbs

Hazards and safety precautions:

Hydrogenperoxide 30 % is toxic, corrosive - can cause serious burns. Eye contact can cause serious injury, possibly blindness. Harmful by inhalation, ingestion and skincontact.

Safety goggles and protective gloves must be worn.

Experimental procedure:

One beaker contains 10 ml of blood; a second beaker is filled with 10 mL of hydogen peroxide 30 %. The two liquids are simultaneously filled into a conical measure.

Results:

The mixture frothes up immediately. Partially the blood is faded.

Video clip (Download RealPlayer .rm file)

Discussion and background:

The enzyme catalase in blood decomposes hydrogen peroxide to form water and oxygen gas:

equation

With foaming, a jelly-like compound is formed. The blood proteins are denaturated and blood dye is partially destroyed.

Hydrogenperoxide is a harmful side-product of many metabolic processes. It acts as a cell poison, damaging and killing cells. So catalase plays an important function in living organisms.

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