Axel Hugo Theorell was born in Linköping, Sweden, on July 6, 1903. He received his bachelor of medicine degree (1924) and his doctor of medicine (1930) from the Karolinska Institute in Stockholm. He also studied at the Pasteur Institute in Paris. When a crippling attack of poliomyelitis made a career as a physician impractical, he decided instead to pursue research and teaching. His academic work while at Stockholm was an inquiry into the chemistry of plasma lipids (fatty acids) and their effect on red blood cells. A technique he developed at this time to separate the plasma proteins albumin and globulin was later to prove useful in his work on isolating enzymes (globular proteins) and coenzymes, which help to activate specific enzymes.

As professor of chemistry at Uppsala University from 1930-1936, Theorell expanded his research on plasma lipids to concentrate on myoglobin, a muscle protein whose oxygen-carrying capacities he compared...