Protein Synthesis

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Protein Synthesis

• Transcription and Translation
• DNA
• Transcription
• RNA
• Translation
• Protein

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RNA

• Structure nucleic acid made up of repeating
  nucleotides similar to DNA
• Consists of ribose sugar, nitrogenous base, and a
  phosphate group

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TYPES OF RNA

• Messenger RNA (mRNA) single uncoiled chain mRNA
  carries genetic information from the nucleus to
  the cytosol
• Transfer RNA (tRNA) about 80 RNA
  nucleotides folded into a
  hairpin shape
  binds to specific amino acids
• Ribosomal RNA (rRNA) RNA nucleotides in a
  globular form rRNA makes up the ribosomes where
  proteins are made

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TRANSCRIPTION

• Process in which genetic information is copied
  from DNA to RNA and is called mRNA
• RNA carries the genetic information from the DNA
  in the nucleus to the cytosol
• This way the information can be used to make
  proteins

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TRANSCRIPTION

• RNA polymerase synthesizes RNA copies of specific
  sequences of DNA
• RNA polymerase the primary transcription enzyme
• RNA polymerase initiates transcription by binding
  to specific regions of DNA (promoters)
• Promoters specific regions of DNA that mark the
  beginning of transcription in the chain, RNA
  polymerase binds to these promoters
• DNA molecule in the region separates when RNA
  polymerase binds
• Template separated DNA chain used for
  transcription
• RNA polymerase adds complementary RNA nucleotides
  to the newly forming RNA molecule (uses
  complementary base pairing)

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TRANSCRIPTION

• Transcription continues until the
  termination signal a specific sequence of
  nucleotides that signifies the end of a gene
• RNA polymerase releases both the DNA molecule and
  newly formed RNA molecule
• All three types of RNA are involved in protein
  synthesis
• mRNA leaves the nucleus and moves into the
  cytosol to direct protein synthesis

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TRANSLATION

• Process of assembling polypeptides from
  information encoded in mRNA by codons
• Codon a combination of three mRNA nucleotides
  that code for a specific amino acid
• Some codons code for translation to start and
  stop
• Start codon (AUG) codes for methionine
• Stop codon (UAA, UAG, UGA) causes translation to
  stop

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TRANSLATION

• When mRNA leaves the nucleus, it migrates to a
  ribosome in the cytosol (this is the site of
  protein synthesis)
• tRNA transports amino acids to the ribosomes
• tRNA has a region that bonds to a specific amino
  acid and on the opposite end, it has an anticodon
• Anticodon three nucleotides that is
  complimentary to and pairs with its mRNA codon
• Ribosomes are composed of rRNA and proteins

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PROTEINS

• Proteins polymers, made up of one or more
  polypeptides
• Polypeptides amino acids linked by peptide bonds
• Sequence of amino acids determines the shape of
  the protein
• The shape (3-D structure) determines the function
  of the protein

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Protein Assembly

• http//nobelprize.org/educational_games/medicine/d
  na/b/translation/translation_ani.html
• http//highered.mcgraw-hill.com/sites/0072437316/s
  tudent_view0/chapter15/animations.html
• http//learn.genetics.utah.edu/content/begin/dna/t
  ranscribe/