Altitudes

Hold up your hands in front of your face. For most people, they will be mirrored copies of each other: You can hold them palm-to-palm and they will match up, but you cannot superimpose them.Molecules also exhibit this handedness, or chirality. They come structured in two mirrored, non-superimposable forms. And it's a fascinating quirk of life that almost all biomolecules will only work in one of their two forms.Natural amino acids – the building blocks of proteins – are almost always left-handed, or sinistral. Natural…