Historically we have separated the disciplines of Chemistry and Biochemistry by recognizing that the distinguishing characteristic of Biochemistry is the catalysis of reactions by enzymes. Enzymes permit metabolic reactions which would otherwise require extremes of temperature, pressure or pH, often associated with Chemistry, to proceed under ambient conditions of the body. Under some conditions chemical reactions occur in vivo in which products of enzymatic reactions proceed to undergo further reactions non- enzymatically with cellular macromolecules. The results can often be seen as toxic...