PARNAS, YAKUB KAROL (1884–1942?), Polish biochemist. Born in Tarnopol, Galicia, Parnas worked at the University of Strasbourg (1914–16), and then directed a physiology institute at Warsaw University. From 1921 he was professor of medical chemistry at Lvov. In 1942, although he had left the Jewish faith, he fled to Russia, where he died. His main work was on biochemistry of muscle and biological synthesis of ammonia. Among his books was Chemja fizjologiczna z szczegolnem uwzględnieniem fizjologji zwierzęcej ("Physiological Chemistry with Special Reference to Animal Physiology," 1922) and together with F. Czapek he edited Monographienaus dem Gesamtgebiet der Physiologie der Pflanzen und der Tiere (1914).