The Central Dogma of Molecular Biology

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The Central Dogma of Molecular Biology

• Jason
• Danielle
• Theresa

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Gene Expression in Eukaryotes

• The gene segment of the DNA strand is
  transcribed, then the 5 cap and poly A tail are
  added to the transcribed RNA, RNA splicing
  occurs, removing the introns from the RNA
  sequence creating the mRNA strand, the spliced
  mRNA strand is then exported out of the cell
  where translation occurs, the mRNA strand is sent
  to the ribosomes where the desired protein is
  made
• Transcription and translation cannot occur at the
  same time due to the fact that they each occur in
  different locations of the cell, transcription in
  the nucleus, translation in the cytoplasm
• Eukaryotes require three different RNA
  polymerases RNA polymerase I, II, III

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Gene Expression in Prokaryotes

• Once RNA polymerase attaches to the promoter
  segment, the mRNA sequence is transcribed
• After the mRNA sequence is made translation
  occurs, creating the instructions needed by the
  ribosomes to make the desired protein
• Transcription and translation can occur at the
  same time
• Prokaryotes require only one RNA polymerase, but
  also have three regulatory elements promoter
  sequence, termination sequence, and operator
  sequence

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TRANSCRIPTION

• RNA polymerase
• enzyme complex that catalyses the transcription
  of DNA to RNA
• begins transcription by binding to the DNA double
  helix at the promoter site
• gradually unwinds the helix, exposing the DNA
  template to be transcribed
• DNA template
• directs the synthesis of RNA from DNA (CG, TA,
  AU)

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TRANSLATION

• mRNA (messenger RNA)
• product of transcription
• travels from the cells nucleus to ribosomes in
  the cytoplasm
• serves as template for protein synthesis
• tRNA (transfer RNA)
• anticodon binds to mRNAs codon
• provides amino acid
• rRNA (ribosomal RNA)
• structural facilitation