American chemist Linus Pauling has made important contributions to a number of fields, including the structure of proteins and other biologically important molecules, mineralogy, quantum mechanics, the nature of mental disorders, nuclear structure, and nutrition. He determined the molecular structure of more than 225 substances using an electron diffraction technique. Pauling was the first to construct the alpha helical structure of a protein. Pauling developed the theory of complementarity and used it to explain enzyme reactions and how genes might act as templates for the formation of enzymes. Using this theory, he studied the relationship between molecular abnormality and hereditary, and was able to determine that sickle cell anemia is caused by the change of a single amino acid in a hemoglobin molecule. Linus Pauling is the only person ever to win two unshared Nobel Prizes. His 1954 Nobel Prize for chemistry was given in recognition of his work on...