Who was most influential?

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Who was most influential?

• Erwin Chargaff
• 11 ratio of A to T
• 11 ratio of C to G
• Linus Pauling
• Laws of chemical bonding that show location of
  atoms in molecules (1928-1935)
• Measured helical proteins
• Rosalind Franklin
• A and B form of DNA
• Distance of one repeat in A form DNA helix
• Confirmed A/G and C/T pairings
• Paired anti-parallel strands
• Maurice Wilkins
• Studied DNA before Watson, Crick and Franklin
• Helped get Franklin hired at Kings College
• Took is own x-ray images of DNA after Franklin
• Realized that needed both experiments,
  mathematical models and physical models to
  understand structure of DNA.
• Later designed a camera that took more detailed
  pictures
• James Watson and Francis Crick
• Put all of the facts together

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Today you will be Code breakers and learn how to
break the code for creating new DNA strands and
how the code in DNA is broken to produce and
make proteins!!
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Do you remember the basic form of DNA?
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DNA Replication

• DNA needs to replicate itself for the purpose of
  cellular division
• Cells need to be created
• To replace cells that have died like skin cells.
  How often to you scratch your skin and see dead
  cells?
• To create a cell (sperm or egg cell) to reproduce
  a new organism

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Steps to DNA replication

• DNA is unwound and unzipped by enzymes
• The DNA code is read by DNA polymerase which adds
  the corresponding nucleotide (Nitrogenous base,
  sugar and phosphate)
• Example Adenine is added to Thymine and Cytosine
  is added to Guanine

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DNA before Replication
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(No Transcript)
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Both DNA Strands are read and a new identical DNA
strand is created.

• If the original DNA strand was ATCGCCGTTA The
  corresponding strand created would be TAGCGGCAAT
• What strand would be created if the original
  strand was AAAACCGGATTT?
• The strand would be TTTTGGCCTAAA
• You are so SMART!!!!!!!!!!!

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Lets try a few more What DNA strand would be
created from the following DNA strand?

• AATTACGCGGCCC
• Did you say TTAATGCGCCGGG
• How about TATATACCGATTTA
• Did you say ATATATGGCTAAAT
• Great!!!

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• The DNA Polymerase serves as a proof reader to
  correct any mistakes
• Mistakes occur in 1/10,000 nucleotides added. An
  error creating a DNA could cause a disease to
  occur or the wrong directions given in another
  part of the cell.
• Fun Fact There are some people who lack DNA
  polymerase and do not have anyone to correct the
  errors in the DNA made. They are more susceptible
  to getting cancer when DNA is damaged from
  exposure to UV rays.

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How is the code read in the DNA to create
proteins and give directions other places in the
cell?

• I need 4 volunteers.

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To make Proteins Step 1 Transcription(make mRNA)

• The code to create proteins which lies in the DNA
  must be carried to a place where there are
  materials for the proteins to be created. Where
  are proteins created?
• DNA is copied to mRNA because DNA is too big to
  leave through the nuclear pores.
• If DNA was not copied the code could not be
  transferred to the place it can be created.

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mRNA is created

• mRNA is created very similarly to how DNA is
  replicated except for mRNA does not have Thymine
  Instead it has uracil so when there is an A in a
  DNA strand the mRNA would have a U.
• The DNA molecule is split open by RNA polymerase
• RNA polymerase looks for a specific code that
  tells it when to start creating RNA called a
  promoter.
• The corresponding Nitrogenous bases are added as
  well as the sugar and phosphate attached.

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Can you break the DNA code?

• If the DNA sequence was ATTCGGCCATT what would
  the mRNA sequence be that was created?
• ___________________________
• Did you say UAAGCCGGUAA
• Yeah!!

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Lets try a few more

• If the DNA sequence was ATTCCGCCGG
• What would the mRNA sequence be?
• Did you say UAAGGCGGCC?
• How about TTCCGCGCGCCGAA?
• Did you say AAGGCGCGCGGCUU
• Great!!!

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Not all sections of DNA that are copied are used
to make proteins.

• Those sections of DNA used to create proteins are
  called exons
• Those sections not used to create proteins are
  called introns and are cut out of the mRNA before
  the protein is made.

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Translationis when proteins are made from the
mRNA

• TrNA (Transfer RNA) is great at breaking
  codes.
• There is a specific code for every three letter
  nitrogenous base sequence
• These three letter sequences are called codons.
• Each codon tells which amino acid to add to the
  protein.

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Three letter Codes are Codons.
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For example.

• GUU signals a transfer mrNA molecule to bring
  Valine a specific type of amino acid.
• If the three letters were GCC the tRNA would
  bring Alanine and add it to the protein.
• Just like building blocks make a wall
• Different amino acids create a unique protein

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If I gave you the RNA sequence of
CGGGUAUUAUGUGAAUGA what series of Amino Acids
would be created into a protein?
Did you say Arginine,Valine,Leucine, Cytosine and
Glutamine?
YOU ROCK!!!!!
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Lets try one more.. If I gave you the MrNA
strand of CGUAGUAGAAGGGCGUGA what Amino Acids
would you bring together?
Arganine, Serine, Argenine, Argenine,Alanine
FABULOSO!!!!!
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Amino Acids connect to make proteins
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Here is a great picture of the whole process.
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To review, I will give you the player. You will
tell me what is does in the process and where it
hangs out. First for DNA replication

• DNA strand
• Enzymes
• DNA polymerase
• Nucleotide
• Nitrogenous Base
• Phosphate

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Now for transcription and translation

• DNA strand
• Nuclear Membrane
• RNA polymerase
• MrNA
• TrNA
• Ribosome
• Codon
• Amino Acid
• Protein

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Your Job.

• Create 2 comic strips
• 1 comic must illustrate how DNA is created for
  creating new cells
• It must include all major players involved
• They must talk about their role in the process in
  your own words
• They must be pictured in the location they do
  their job.

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The other comic.

• Illustrates transcription and translation
• (How mRNA is created and the code from a DNA
  molecule allows a unique protein to be made)
• This comic must represent each player involved.
• Each player must talk about their individual role
  in the process
• Each player must be located in the environment
  they do their job.

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This will be due Next Monday/Tuesday.

• You will have a work day Wednesday/Thursday