Alexander Fleming was a Scottish biochemist and physician who was the first to discover the antibiotic penicillin. Fleming was born in Ayrshire, Scotland in 1881. He attended the Robert Gordon's College in Aberdeen and the University of St. Andrews, where he studied medicine. He began his career as a researcher at the London Hospital in 1902. Fleming began working on penicillin in 1928, after he observed that the mold Penicillium notatum killed bacteria. He isolated the active ingredient in penicillin in 1929 and was awarded the Nobel Prize in Physiology or Medicine in 1945. Fleming died on March 11, 1955.