If poly A is added to poly U, to form a double or triple helix, the combination is inactive.
Francis CrickAlmost all aspects of life are engineered at the molecular level, and without understanding molecules we can only have a very sketchy understanding of life itself.
Francis CrickIt is one of the more striking generalizations of biochemistry - which surprisingly is hardly ever mentioned in the biochemical textbooks - that the twenty amino acids and the four bases, are, with minor reservations, the same throughout Nature.
Francis Crick