James B. Sumner

James Batcheller Sumner was born November 19, 1887, an American biochemist working at a time when the chemical nature of enzymes was still unknown. He discovered that enzymes can be crystallized, a breakthrough that allowed scientists to study their structure with precision. More fundamentally, he was the first to prove that enzymes are proteins, settling a debate that had stalled the field. The work earned him the Nobel Prize in Chemistry in 1946, shared with John Howard Northrop and Wendell Meredith Stanley. He died August 12, 1955, having cracked open a door that biochemistry has walked through ever since.