BIOSC-101 Lecture Notes - Lecture 15: Norman Horowitz, Srb, Arginine
20 Jun 2020
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Document Summary
Biologists in the early 20th century made tremendous progress in understanding how genes are inherited. A hypothesis on what genes actually do did not appear until 1941 (beadle and. To study gene function, creating loss-of-function alleles and analyzing their effects is a common research strategy. Loss-of-function alleles do not produce a functioning gene product. Beadle and tatum exposed n. crassa cells to radiation and found mutants that could not make specific compounds. They found lack of vitamin b6 synthesis was due to a defect in a single gene. Beadle and tatum proposed the one gene, one enzyme hypothesis: each gene is responsible for making one enzyme. Adrian srb and norman horowitz tested their hypothesis. Previous work had shown n. crassa cells are able to synthesize their own arginine. They irradiated cells and screened for mutants that could not produce arginine. N. crassa that lack one of the above enzymes cannot grow unless they are supplemented with arginine.
