CAS BI 108 Study Guide - Midterm Guide: Archibald Garrod, Ribosomal Rna, Start Codon
16 May 2016
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Document Summary
Observations in humans led to the proposal that genes determine enzymes. Identification of a gene product as a protein began with mutation. Mutated allele= inactive enzyme and homogentisic acid accumulated instead of harmless product. Garrod- one gene to one enzyme- inborn error of metabolism . Experiments on bread mold established that genes determine enzymes. Model organisms: easy to manipulate experimentally; easy to grow, short generation times, easy to manipulate genetically, large number of offspring. Used to develop principles of genetics to apply generally to other organism. Garrod, beadle and tatum - hypothesis: expression of specific gene= activity of specific enzyme. Treated with x rays (mutagen: damages dna cause mutations: heritable alterations in dna sequence) Some could no longer grow unless supplied with added nutrients. B+ t hypothesis: genetic strains had mutation in gene that code production of enzyme to make additional nutrients. Found single compound support growth of strain. Each mutation cause defect in one enzyme in a metabolic pathway.
