Alexander Ivanovich Oparin (; in English, Aleksandr Ivanovich Oparin) ( in Uglich, Russia – April 21, 1980 in Moscow, Soviet Union) was a Soviet biochemist notable for his untested theories about the origin of life, and for his book The Origin of Life. He also studied the biochemistry of material processing by plants and enzyme reactions in plant cells. He showed that many food-production processes were based on biocatalysis and developed the foundations for industrial biochemistry in the USSR.