BIOL 3450 Chapter 5: Chapter 5 – Fundamental Molecular Genetic Mechanisms
Document Summary
Different types of rna exhibit various conformations related to their functions: ribozymes ~ catalytic rnas. Dna is replaced by pyrimidine uracil (u) in rna: adjacent nucleotides in polynucleotide are linked by phosphodiester bonds entire strand has chemical directionality with 5" and 3 ends. 5. 2 transcription of protein coding genes and formation of functional mrna. Rna polymerase and polymerase dissociates from template dna once released, rna polymerase is free to transcribe same gene again or another gene. In eukaryotic dna, each protein coding gene is transcribed from its own promoter. Messenger rna carries information from dna in three letter genetic code: genetic code ~ triplet code in which every three nucleotide sequence or codon, is read from specified starting point in mrna. Folded structure of trna promotes its decoding functions: aminoacyl trna ~ trna molecule chemically linked to particular amino acid via high energy bond. Translation is terminated by release factors when stop codon is reached: release factors (rfs) ~
