Did clay mould life’s origins?

Science - Cath Harris | 01 Apr 11. An Oxford University scientist has taken our understanding of the origin of life a step further. Professor Don Fraser from the Department of Earth Sciences has carried out neutron scattering experiments to try to find out more about the role of geochemistry in determining the origin of our amino acids - key building blocks of life on Earth - and specifically why the DNA-coded amino acids that make up our proteins are all left-handed. There are two varieties of amino acids, known as left- or right-handed (referred to as S and R). They are mirror images of each other and both exist in nature, as shown for other substances by Louis Pasteur. Biochemical processes in living organisms use left- and right-handed or 'chiral' receptors that template differently with these two forms. The olfactory receptors in our noses, for example, easily distinguish the distinct smells of the otherwise identical molecules (called carvones) of spearmint (R-carvone) and caraway (S-carvone).