BIOL 117 Lecture Notes - Lecture 3: Genetic Screen, Reading Frame, Francis Crick
21 Aug 2016
School
Department
Course
Professor
Document Summary
George beadle and edward tatum proposed: damage a gene by creating a mutant, then observe the resulting effect on mutant"s phenotype. Nonfunctional alleles are now called knock-out, null, or loss-of-function alleles. Srb and horowitz further tested the one-gene, one-enzyme hypothesis. Examined production of the amino acid arginine. Arginine is produced via a metabolic pathway requiring three enzymes. Srb and h hypothesized different genes lead to synthesis of the three enzymes. To test their hypothesis: used radiation to create thousands of mutant individuals, performed a genetic screen, it allowed them to select those mutants incapable of producing genes. If supplementing with c allows the mutant to grow, then we would know it"s enzyme 2. Rna molecules act as a link between genes found in the cell"s nucleus. Rna polymerase synthesizes rna from information in dna. The central dogma summarizes the flow of information in cells. Many genes code for rna molecules: do not founction as mrnas, are not translated into proteins.
