Making Proteins

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Making Proteins
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Proteins

• The job of DNA is to provide the instructions for
  making protein

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Proteins

• Proteins do the daily business of living, giving
  cells their shapes and unique abilities
• Movers, enzymes, supporters, defenders
• Lifes diversity results from differences in
  kinds and arrangements of protein molecules

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Proteins

• What is a protein?
• Long chain of amino acids hooked together
• Only 20 amino acids exist, but they can be
  combined countless ways

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Proteins Genes

• Genes have the instructions for what amino acids
  to link together and in what order they should be
  linked
• 1 gene has the directions for 1 protein
• DNA molecules are just genes after genes after
  genes (directions for proteins, after proteins

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What determines the order of amino acids?

• THE GENETIC CODE!
• The genetic code consists of only 4 letters! Can
  anyone guess what they are?
• A, T, G and C

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What determines the order of amino acids?

• The order of nucleotides/nitrogen bases
  determines what amino acids are used to make a
  protein
• Codonset of three nitrogen bases in a row that
  code for an amino acid

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• T G A A C T G T T A T A
• How many codons are present?
• How many amino acids will be made?

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Protein Synthesis

• Has two parts
• Transcription
• Translation

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Transcription

• Creating a copy of mRNA from DNA
• DNA does not turn into mRNA
• DNA must stay in the nucleus where it is
  protected and can be repaired
• mRNA will leave the nucleus, and go the ribosome
  where the protein will be made
• The mRNA copy is COMPLEMENTARY not identical to
  DNA

• http//www.youtube.com/watch?vq1fIdUArthU

• http//www.youtube.com/watch?vmQClpqDBlSs

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Differences between DNA RNA
Deoxyribose
Ribose
Same
Same
A C G T
A C G U
Two
One
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Practice transcription

• G C T A T C A A T C G G
• C G A U A G U U A G C C
• T T A A T A C G T T C G G
• A A U U A U G C A A G C C
• C C A C G T G C A T
• G G U G C A C G U A
• A G C T T A G C C A T
• U C G A A U C G G U A

DNA
mRNA
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Translation

• Actual protein construction, mRNA provides the
  instructions to join amino acids together
• Transfer RNA (tRNA) with the help of ribosomal
  RNA (rRNA) reads the mRNA
• Occurs at the ribosome
• Anticodonset of three nitrogen bases on tRNA
  that match a codon on mRNA

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DNA TTT ACC TAC mRNA AAA UGG AUG
trp
lys
met
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Practice Translation

• G C T A T C A A T C G G
• C G A U A G U U A G C C
• arg----stop
• T T A A T A C G T T C G G
• A A U U A U G C A A G C C
• asp-----tyr-----ala-----ser----

DNA
Transcription
mRNA
Translation
Protein
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Practice Translation

• C C A C G T G C A T
• G G U G C A C G U A
• gly------ala-----arg-----
• A G C T T A G C C A T
• U C G A A U C G G U A
• ser------asp-----arg---------

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Practice Transcription Translation

• http//learn.genetics.utah.edu/units/basics/transc
  ribe/

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• http//www.lewport.wnyric.org/JWANAMAKER/animation
  s/Protein20Synthesis20-20long.html
• Lew ports biology placegood general overview of
  protein synthesis
• http//www.wisc-online.com/objects/index_tj.asp?ob
  jIDAP1302
• Protein synthesis

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• http//www.youtube.com/watch?vNJxobgkPEAo
• Nice overview
• http//www.youtube.com/watch?vyZ_IPafioSU
• newton
• http//www.youtube.com/watch?vMl0OqAUzEXU
• Complicated RNA shows good proteins building at
  ribosome