Herschel K. Mitchell

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Herschel Kenworthy Mitchell (born November 27, 1913 in Los Nietos near Los Angeles , † April 1, 2000 ) was an American biochemist.

Mitchell studied chemistry at Pomona College with a bachelor's degree in 1936, Oregon State College with a master's degree in 1938, and at the University of Texas, where he received his PhD in organic chemistry and biochemistry in 1941. From 1943 he was with George Wells Beadle at Stanford University , where he worked as a chemist in the geneticist group of Beadle in the genetics especially of Neurospora (the fungus that the group used as a model organism), and started with this in 1946 the Caltech , where he became associate professor in 1949 and 1953, Professor of Biology.

At Beadle he dealt with biochemical genetics and was the first to prove the lack of an enzyme (tryptophan synthetase) in a mutant of Neurospora. This was an important piece of evidence in Beadle's one-gene, one-enzyme hypothesis.

In 1941 he isolated folic acid (from 4 tons of spinach) and recognized its vitamin character.

He dealt extensively with biosynthesis in Neurospora, including in 1951 he isolated orotidine from Neurospora. From the 1950s he turned to Drosophila and its developmental biology. He also worked with Ernst Hadorn .

In the 1970s, he pioneered the biochemistry of heat shock . He and Alfred Tissières discovered in 1973 that after a heat shock, a small group of new proteins is synthesized and the production of most of the others is blocked.

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personal data
SURNAME Mitchell, Herschel K.
ALTERNATIVE NAMES Mitchell, Herschel Kenworthy (full name)
BRIEF DESCRIPTION American biochemist
DATE OF BIRTH November 27, 1913
PLACE OF BIRTH Los Nietos near Los Angeles
DATE OF DEATH April 1, 2000