John Howard Northrop (July 5, 1891 – May 27, 1987) was an American biochemist who won the Nobel Prize in Chemistry in 1946 (with James Batcheller Sumner and Wendell Meredith Stanley) for purifying and crystallizing certain enzymes. Jump to: navigation, search July 5 is the 186th day of the year (187th in leap years) in the Gregorian Calendar, with 179 days remaining. ... Jump to: navigation, search 1891 was a common year starting on Thursday (see link for calendar). ... May 27 is the 147th day (148th in leap years) of the year in the Gregorian calendar, with 218 days remaining. ... Jump to: navigation, search 1987 is a common year starting on Thursday of the Gregorian calendar. ... List of Nobel Prize laureates in Chemistry from 1901 to the present day. ... Jump to: navigation, search 1946 was a common year starting on Tuesday. ... James Batcheller Sumner (November 19, 1887 - August 12, 1955) was an American chemist. ... Wendell Meredith Stanley (August 16, 1904 - June 15, 1971) was an American biochemist, virologist and Nobel prize laureate. ...

Northrop was born in Yonkers, New York and educated at Columbia University, where he earned his PhD in chemistry in 1915. During World War I, he conducted research for the U.S. Army Chemical Warfare Service on the production of acetone and ethanol through fermentation. This work led to studying enzymes. Yonkers, just north of New York City in Westchester County, is the fourth largest city in the U.S. state of New York, with a population of 196,086 (according to the 2000 census). ... Jump to: navigation, search Columbia University is a private university in the Morningside Heights neighborhood of Manhattan, New York City. ... Jump to: navigation, search World War I was primarily a European conflict with many facets: immense human sacrifice, stalemate trench warfare, and the use of new, devastating weapons - tanks, aircraft, machineguns, and poison gas. ... Jump to: navigation, search For an alternate use of acetone, see Acetone (music). ... Jump to: navigation, search Ethanol, also known as ethyl alcohol or grain alcohol, is an inflammable, colorless chemical compound, one of the alcohols that is most often found in alcoholic beverages. ... In its strictest sense, fermentation (formerly called zymnosis) is the energy-yielding anaerobic metabolic breakdown of a nutrient molecule, such as glucose, without net oxidation. ...

In 1929 he isolated and crystallized the gastric enzyme pepsin and determined that it was a protein and in 1938 he isolated and crystallized the first bacteriophage (a small virus that attacks bacteria), and determined that it was a nucleoprotein. Northrop also isolated and crystallized pepsinogen (the precursor to pepsin), trypsin, chymotrypsin, and carboxypeptidase. Pepsin is a protease, a digestive enzyme that degrades food proteins in the stomach. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... A phage (also called bacteriophage) (in Greek phageton = food/consumption) is a small virus that infects only bacteria. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... A nucleoprotein is any protein which is structurally associated with nucleic acid (either DNA or RNA). ...

His 1939 book Crystalline Enzymes was an important text. Northrop was employed by the Rockefeller Institute for Medical Research in New York City from 1916 to 1961, at which time he retired. Northrop died in Wickenberg, Arizona. Rockefeller University is a small private university focusing primarily on graduate education and research in the biomedical fields, located between 63rd and 68th street on York Avenue on the Upper East Side of Manhattan island in New York City, New York. ...

External links

• Nobel Prize biography