RNA Transcription

Creates RNA from DNA

Inititation

• Transcription factors bind to TATA box
  • Hormones go into receptors, creating transcription factors
• RNA Polymerase III recognize factors to find beginning of gene
• Polymerase starts transcribing at initiation site

Elongation

• Separates DNA helix and synthesizes mRNA in its active site
• Nucleotides are bonded with hydrogen bonded using dehydration synthesis

Termination

• In prokaryotes, encourages polymerase to fall off using U’s
  • Bond between A and U is weaker
  • Running out of U’s will cause slowing down
  • Hairpin loop takes up space

Editing

• Cannot edit RNA in prokaryotes due to lack of nucleus
• In eukaryotes, RNA is edited in nucleus to increase stability
  • Nucleic acid cap is put on 5’ side
    • Serves as recognition point for proteins
  • Poly-A polymerase adds A’s to 3’ end
    • Self-destructs after time to counter deamination of C
  • mRNA transcripts are spliced to remove intron sequences
    • Introns are segments without coding information