John Cornforth

John Warcup Cornforth was born in Australia on 7 September 1917 and trained as a chemist across two Commonwealth nations. His life's work centered on a deceptively simple question: when an enzyme rewires an organic molecule, which hydrogen atoms does it actually replace? By synthesizing terpenes, olefins, and steroids and then watching enzymes operate on them, he pinpointed the precise clusters of hydrogens that shifted during each transformation. That specificity let him chart the step-by-step biosynthesis of cholesterol - a map no one had drawn before. In 1975 he shared the Nobel Prize in Chemistry with Vladimir Prelog for his work on the stereochemistry of enzyme-catalyzed reactions. He was knighted two years later and continued working until his death on 8 December 2013.