The biology of smell is a mystery — AI is helping to solve it

We smell by detecting molecules around us — but knowing the chemical structure of a molecule tells you almost nothing about its odour. Even categorising what we perceive is difficult: there is no palette of scent ‘primary colours’ as there is for vision. And olfactory receptor proteins are hard to work with, so what they look like and how they function has mostly been guesswork. But that isn’t stopping scientists from trying, with help from innovations in structural biology, data analytics and artificial intelligence.