A New Twist on Chirality

One of the great mysteries in science is the homochirality (single handedness) of the essential molecules of life. Natural sugars are almost exclusively right-handed; natural amino acids are almost exclusively left-handed. Current life forms could not exist without the uniform chirality of these monomers, which form the building blocks of polysaccharides and proteins. Uniform chirality is also essential for information storage and processing, as demonstrated by the supramolecular chirality of the DNA helix. But we still do not know the origin of this biomolecular homochirality.