FOR HIS PIONEERING WORK on nucleic acids, Alexander Rich, a professor of biophysics at MIT, has won the 2008 Welch Award in Chemistry. The $300,000 award is given annually by Houston’s Welch Foundation to foster and encourage basic chemical research that benefits humankind. A student of Linus Pauling’s and a contemporary of James Watson and Francis Crick’s, Rich has devoted his entire career to studying DNA and RNA. In 1979, he and his colleagues discovered left-handed DNA, which they named Z-DNA for its zigzag backbone. Since then, Rich’s research has focused on Z-DNA’s importance in biological systems. In addition, Rich discovered and solved the three-dimensional structure of the RNA double helix. He was the first scientist to carry out DNA-RNA hybridization and to discover DNA’s presence in organelles. He also discovered polyribosomes, which are clusters of ribosomes attached to messenger RNA, and determined the three-dimensional structure of transfer RNA. Rich is known for his enthusiasm ...