Transcription

  • initiation
    • RNA polymerase binds to promoter
    • unwinds and opens the DNA section of wanted gene
  • elongation
    • RNA polymerase adds nucleotides in 5’-3’ directions
    • (covalent bonds between ribose and phosphates)
  • termination
    • RNA polymerase reaches terminator region and releases mRNA
  • *PROKARYOTES = DONE HERE : the mRNA and ribosomes → polypeptides
  • *EUKARYOTES CONTINUES
    • modify the mRNA before translation with “post-transcription”
  • post-transcription
    • splice exons (joining them)
    • (introns are removed and stay in nucleus)
    • and then adds 5’cap and poly A tail
    • mature mRNA exits nucleus towards cytoplasm