RNA synthesis and processing

  1. transcription
    process of synthesizing RNA from DNA
  2. initiation
    the initiation of transcription is directed by DNA sequences called promoters which tell the RNA polymerase where to begin
  3. promoters
    the short stretch of DNA that tells the RNA polymerase where to begin transcription
  4. elongation
    the template (non-coding) strand of DNA is used as a template by RNA polymerase to add nucleotides in a 5' to 3' direction
  5. termination
    certain DNA sequences function as signals to tell the RNA polymerase to terminate transcription
  6. describe capping of hnRNA to mRNA
    mRNA are capped at their 5' ends with 7-methylguanylate by guanylyl transferase. The capping protects it from exonuclease activity
  7. describe polyadenylationf of hnRNA to mRNA
    • Addition of adenylate residues to the 3' terminus of mRNA is cataylzed by poly A polymerase.
    • The poly A tail slows the exonucleolytic degradation of mRNA
  8. describe splicing of hnRNA to mRNA
    removal of introns (non coding sequences) while leaving exons (coding seuqences)
  9. describe the processing of rRNA
    Both prokaryotes and eukaryotes are synthesized as large precursors. the precursor rRNA are processed into their mature form by nucleases and methylases
  10. describe the processing of tRNA
    prokaryotes and eukaryotes are also transcribed as precursors which are cleaved and extensively modified
  11. which antibiotic inhibits prokaryotic RNA polymerases
  12. RNA I polymerase transcribes
  13. RNA polymerase II transcribes
  14. RNA polymerase III transcribes
Card Set
RNA synthesis and processing
includes processing of hnRNA and mRNA