ABSTRACT
Metabolic pathways within organisms require a sequence of consecutive reactions to take place. These are mediated by enzymes and involve an apparently complex range of changes to biomolecules. The processes can be understood in terms of the reactions of simple organic compounds. These reactions can be classied into a small range of simple mechanisms such as substitution, addition, and elimination that may take place at specic reactive centres within a molecule. An understanding of the charge distribution around a chemical bond and a recognition of such centres allows simple reactions to be predicted. The reactions of large biomolecules can then be explained by analogy with model organic molecules.
