How was John Howard Northrop awarded the Noble Prize?

Name: John Howard Northrop
Country: New York U.S.
Date of Bitrh: July 5, 1891
Date of Death: May 27, 1987 (Arizon)
Subject of Study: Crystallization and Enzymes
Noble Prize Year: Nobel Prize for Chemistry in 1946 for successfully purifying and crystallizing certain enzymes, thus enabling him to determine their chemical nature.
About: Northrop was educated and received his doctorate in chemistry in 1915 at Columbia University. In World War 1, he was a captain in the U.S. Army Chemical Warfare Service.
During World War I, Northrop conducted research on fermentation processes suitable for the industrial production of acetone and ethyl alcohol. This work led to a study of enzymes essential for digestion, respiration, and general life processes. At that time, the chemical nature of enzymes was unknown, but through his research, Northrop was able to establish that enzymes obey the laws of chemical reactions. He crystallised Pepsin, a digestive enzyme present in Gastric Juice, in 1930 and found that it is a protein. He isolated in 1938 the first bacterial virus (bacteriophage), which he proved to be a nucleoprotein and their inactive precursors, trypsinogen and chymotrypsinogen.
Northrop was first an assistant at, and then a member of, the Rockefeller Institute for Medical Research in New York City from 1916 until his retirement in 1961, when he became professor emeritus. He was also a visiting professor of bacteriology and biophysics at the University of California at Berkeley (1949–58). His book, Crystalline Enzymes (1939), was an important text.