The biochemical reactivity of O2 and

However, H2O2 (hydrogen peroxide), formed by the reaction above and by leakage of electrons out of the respiratory chain, is a powerful oxidizing agent and also harmful to cells. It is metaboHzed further by catalases and peroxidases. A catalase catalyzes the reaction 

We need to understand how electronic structure affects the reactivity of moiecuies such as NO (a biochemical messenger). 

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