Hydrogen peroxide (H2O2) is a combination of hydrogen and oxygen. In high concentrations, it can be unstable and even poisonous. In lower concentrations, such as the types found in many homes, it works well as a disinfectant and antiseptic.The reason behind foaming of Hydrogen peroxide is because blood and cells contain an enzyme called catalase. Since a cut or scrape contains both blood and damaged cells, there is lots of catalase floating around.When the catalase comes in contact with hydrogen peroxide, it turns the hydrogen peroxide (H2O2) into water (H2O) and oxygen gas (O2).Catalase does this extremely efficiently -- up to 200,000 reactions per second. The bubbles that can be seen in the foam are pure oxygen bubbles being created by the catalase.Hydrogen peroxide does not foam in the bottle or when in contact with skin because there is no catalase to help the reaction to occur. Hydrogen peroxide is stable at room temperature. http://www.wisegeek.org/what-is-hydrogen-peroxide.htm
Enzymes are global proteins that act as catalystto biochemical reactions in living cells. A catalyst alters the speed of a chemical reaction without itself undergoing any permanent change. An enzyme is a biological catalyst that increases the rate of chemical reaction by lowering the level of activation energy necessary to start the reaction. Enzymes speed up these reactions by bringing the reactants into close proximity and facilitating their interaction. Liver contains a specific enzyme called catalase. Enzyme molecules have a small region that is functional, called the active site. In an enzyme-catalyzed reaction, the substrate binds to the active site and forms enzyme-substrate complex with the enzyme. The enzyme then breaks the bonds in the substrate. The product ofthe reaction then leaves the enzyme, which remains unchanged after the reaction. Catalase in an enzyme produced by our liver to break down hydrogen peroxide – a...
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