James B. Sumner

James B. Sumner was an American chemist who crystallized urease and showed that enzymes can be proteins. He shared the 1946 Nobel Prize in Chemistry.

John Howard Northrop: An American biochemist who crystallized digestive enzymes and showed that they are proteins. His independent enzyme crystallizations reinforced Sumner’s claim that enzymes are proteins.
Urease: An enzyme that catalyzes the hydrolysis of urea into ammonia and carbon dioxide. Sumner purified and crystallized this enzyme, making it the centerpiece of his evidence.
Cornell University: A private research university in Ithaca, New York, founded in 1865. Sumner conducted the urease research that established his scientific reputation at Cornell.
Protein: A large biological molecule made of amino acids linked into one or more chains. Identifying urease as a protein supported the view that proteins could perform specific catalytic work.
Wendell Meredith Stanley: An American biochemist who crystallized tobacco mosaic virus and shared the 1946 Nobel Prize in Chemistry. He shared the Nobel Prize with Sumner and Northrop for work on enzymes and viruses.
Enzyme: A biological catalyst that accelerates chemical reactions without being consumed by them. Sumner’s work established that enzymes could have the chemical character of proteins.
Agricultural chemistry: The study of chemical processes in soils, crops, livestock, and agricultural products. Sumner’s training and early research connected enzyme chemistry to agricultural science.
Biochemistry: The study of chemical substances and reactions in living organisms. Sumner’s work helped make purified biological molecules central subjects of experimental chemistry.
Richard Willstätter: A German organic chemist who received the 1915 Nobel Prize in Chemistry for research on plant pigments. His influential view treated enzymes as nonprotein carriers, opposing the conclusion Sumner reached.
Protein crystallization: The formation of ordered solid crystals from purified protein molecules. Sumner’s urease crystals made enzyme purification visible and experimentally testable.

Linked from 2 pages