Transcription

• carries out protein synthesis in ribosomes


  rrna
• carries genetic code for proteins

  mrna
• incorporate amino acids into polypeptide chain

  trna
• processing of pre-mrna


  snrna
• processing and assembly of rrna

  snorna
• probes


  scrna
• inhibits translation of mrna

  mirna
• triggers degradation of other rna molecules

  small interfering rna
• regulate gametogenesis


  pirna
• a dna sequence that the transcription apparatus recognizes and binds

  promoter
• a sequence of dna nucleotides that is copied into an rna molecule


  rna coding region
• a sequence of nucleotides that signals where transcription is to end

  terminator
• synthesized from ribonucleoside triphosphates


  rna
• required to identify the correct sites for transcription initiation

  sigma subunit
• chain initiation and interaction with regulatory proteins

  alpha
• chain initiation and elongation

  beta
• dna binding


  beta prime
• promoter recognition


  sigma
• stretch of dna that encodes an rna (promoter, rna coding, terminator)

  transcription unit
• dna sequence to which rna polymerase binds to initiate transcription

  promoter
• rna polymerase where transcription starts

  transcription bubble
• binding of rna polymerase to promoter region on dna

  preinitiation complex
• strengthens affinity of core to promoter

  sigma
• determines upstream element


  c terminal domain of alpha subunit
• transcription initiation


  closed promoter complex

  open promoter complex

  incorporating nucleotides

  promoter clearance
• this is where rna molecule will attach for transcription

  crabclaw
• does not require protein for termination

  intrinsic termination
• features of rho-independent termination

  inverted repeats

  6 adenine nucleotides follow the 2nd inverted repeat
• signaled by a gc-rich inverted repeat followed by four a residues

  termination of transcription
• essential transcription protein in prokaryotes

  rho
• three route of p-dependent termination

  catch up recycling

  catch up decomposing

  stand-by decomposing
• binding of rna polymerase and local unwinding of dna

  initiation
• nucleotides are added to the 3' end of the growing rna strand


  elongation
• synthesized rna strand is released

  termination
• makes large rRNA precurosr

  polymerase I
• makes hnRNA and small nuclear rna

  polymerase ii
• makes precursors to trna, 5s rrna

  polymerase iii
• promoter that is dependent on the type of gene to be transcribed


  tata box
• genes constantly expressed in all cells

  housekeeping genes
• genes expressed only when their products are needed

  luxury genes