Nathan Oram Kaplan (June 25, 1917 – April 15, 1986) was an American biochemist who studied enzymology and chemotherapy. After completing a B.A. in chemistry at UCLA in 1939, Kaplan studied carbohydrate metabolism in the liver under at the University of California, Berkeley medical school. He earned his Ph.D. in 1943. From 1942 to 1944, Kaplan participated in the Manhattan Project, and then spent a year as an instructor at Wayne State University. From 1945 to 1949, Kaplan worked with Fritz Lipmann at Massachusetts General Hospital to study coenzyme A. Kaplan went to the University of Illinois College of Medicine as an assistant professor in 1949, and from 1950 to 1957 he worked at the of Johns Hopkins University. In 1957, he was recruited to head a new graduate program in biochemistry at