BIOL 112 Lecture 18: Lecture 18 - Genetic Code.pdf

• School: McGill University
• Department: Biology
• Course: BIOL 112
• Professor: Frieder Schoeck

Document Summary

Proposed one gene one enzyme following observations with alkaptonurea ! Recessive hereditary trait resulting from a genetic error ! No enzyme to break down tyrosine (homogentiate 1,2 dioxygenase) ! Each gene corresponds to a speci c enzyme ! Clari ed the relationship between genotype and phenotype ! Demonstrated that one gene encodes one enzyme ! Hypothesis: there should be a mutant allele corresponding to every enzyme in a pathway ! !- tested spores which required certain chemicals in the pathway to supplement their growth -> exposed mild to x-rays so that it became auxotrophic ! Auxotrophs: the inability of an organism to synthesize a particular organic compound required for its growth ! Wildtype were phototrophic, mutants were auxotrophic ! Supplementing the mild with the substance they were no longer able to synthesize allowed for. Conclusion: each gene speci es a particular enzyme ! its growth and rescue the mold ! Modi ed to: one gene -> one protein !