Handing handedness to amino acids

Why ‘life is handed’ – why the chiral amino acids that make up proteins and the chiral sugars in nucleic acids are present only in one of the two possible enantiomeric forms – is one of the most tantalising questions for chemistry. It’s tantalising precisely because, in contrast to the origin of life itself from abiotic chemical resources, it seems to be a question simple and clear enough to resolve, after a fashion. We might never have a definitive answer, since there seems little prospect of gleaning sufficient clues from the geological record to identify a single best hypothesis. But it doesn’t seem too much to hope that we could say with some confidence ‘this route, at least, would have worked’.