Ochoa, Severo (sāvā`rō ōchō`ä), 1905–93, American biochemist and educator, b. Spain, M.D. Univ. of Madrid, 1929. After teaching at the universities of Madrid, Heidelberg, and Oxford, he came to the United States in 1940. In 1954 he was appointed chairman of the department of biochemistry at New York Univ. He became an American citizen in 1956. With Arthur Kornberg he received the 1959 Nobel Prize in Physiology or Medicine for the synthesis of ribonucleic acid (RNA), an organic compound that carries hereditary qualities in all reproduction.

Ochoa, Severo

(born Sept. 24, 1905, Luarca, Spain—died Nov. 1, 1993, Madrid) Spanish-born U.S. molecular biologist. He received his M.D. and subsequently studied in Germany and Britain before immigrating to the U.S. in 1941, where he taught principally at New York University. In 1955, while researching high-energy phosphates, he discovered an enzyme in bacteria that enabled him to synthesize RNA. The enzyme normally breaks down RNA, but in a test tube it runs its natural reaction in reverse. It has been valuable in enabling scientists to understand and recreate the process whereby the hereditary information contained in genes is translated into enzymes that determine each cell's functions and character. With Arthur Kornberg he received a 1959 Nobel Prize.

Ochoa, Severo (1905–93) molecular biologist; born in Luarca, Spain. He taught and performed research in Europe before coming to the U.S.A. to join Washington University (St. Louis) (1941–42). At New York University (NYU) (1942–74), he described the mechanism of the Krebs citric acid cycle, which generates cellular energy (1940s–1950s). In 1955 he isolated a bacterial enzyme with which he performed the first test-tube synthesis of various RNAs, enabling the eventual deciphering of the genetic code. For this he won one-half the 1959 Nobel Prize in physiology. After retiring from NYU, he moved to the Roche Institute for Molecular Biology (New Jersey) (1974–85), then returned to Spain as a professor at Universidad Autonoma, Madrid (1985).