Open an undergraduate biochemistry textbook and you will learn that enzymes are highly efficient and specific in catalyzing chemical reactions in living organisms, and that they evolved to this state from their "sloppy" and "promiscuous" ancestors to allow cells to grow more efficiently. This fundamental paradigm is being challenged in a new study by bioengineers at the University of California, San Diego, who reported in the journal Science what a few enzymologists have suspected for years: many enzymes are still pretty sloppy and promiscuous, catalyzing multiple chemical reactions in living cells, for reasons that were previously not well understood.
