and discovered that the course faculty were listed as Blum, Cook, and Goddard.

For his doctoral research Goddard studied the metabolism and nutrition of a dermatophyte fungus, Trichophyton. This led to his later interest in protein structure. He stayed on at Berkeley for a year after his degree, as a teaching fellow. During this year he and Fred Uber investigated the X-ray killing of spores of the fungus Neurospora. In this research many mutant spores were produced, including some that were nutritionally deficient. Some of these mutants were given to B. O. Dodge and served as markers in his genetic work. It might be said that Uber's and Goddard's work set the stage for the later work of George Beadle and Edward L. Tatum, their one-gene/one-enzyme hypothesis and the 1958 Nobel Prize, which they shared with Lederberg.

The following year Goddard was awarded a National Research Council fellowship to work with Leonor Michaelis at the Rockefeller Institute in New York. There he assimilated Michaelis's concept that the oxidation of organic compounds occurs in single electron steps (semiquinones) and later published a landmark paper with James LuValle that laid the foundation for what are now known as free radical reactions in biology.

Michaelis was not interested in the Neurospora work that Goddard had done, but he was excited when Goddard showed him that keratin (hair, wool, feathers), which is not normally digested by proteolytic enzymes, could be so digested if the disulfide bonds were first reduced. He and Michaelis showed that the fibrous structure of the protein could be degraded by reduction of the disulfide bonds:

2 H⁺ + R—S—S—R → 2 R—SH