Transcript Gene to Protein

DNA to RNA
The first step in - How DNA makes you
How to Bake Grandma’s Cookies
(Another Food Analogy to Help You Learn Biology)
1. Copy the recipe from Grandma’s family secret recipe
file.
• Location of recipe Grandma’s house
• Product Written instructions to
make the best cookies
in Quakertown, PA
Grandma lives in a retirement home,
so she doesn’t cook.
You will have to copy Grandma’s recipe in
order to leave Grandma’s & go to your
kitchen where you will find the ingredients
and utensils to make the cookies.
2. Read and follow instructions
• Add:
correct ingredients
correct amounts
correct order
• bake for required time
• Product:
Best cookies in town!
How is this analogous to biology?
• How does the information (recipe) produce
the cookies (product)?
• How does the information in genes (sections
of DNA) produce the proteins (products) that
make our traits?
• What are the “products” that cause you to
look and function as you?
Review: Proteins
• Polymers of amino acids (monomers)
• The Order of Amino Acids determines the 3D shape
of a protein
• Structure (3-D) determines function
• 7 categories:
1. Structure
2. Movement
3. Storage
4. Defense
5. Transport
6. Signaling
7. Enzymes
DNA contains the “recipe” for every
protein in your body
Information is copied in the nucleus
Copy leaves nucleus  cytoplasm
Information used to assemble proteins
• Trait: freckles, bent pinky, floppy earlobes,
curly hair
The Big Picture: 2 steps in protein synthesis
1. Transcription
information from
gene is copied
2. Translation
Information is used
to assemble amino
acids into proteins
 Physical Traits are
determined by
those proteins
DNA – Original Text
of Information
mRNA - Working copy
of instructions
Three types of RNA:
Messenger RNA (mRNA)
Copies information from DNA
Transfer RNA (tRNA)
Transports correct amino acids
to build protein
Ribosomal RNA (rRNA)
Helps form ribosomes: the workbench where
proteins are assembled
Transcription: Why
• Information from a
single gene is
copied to make
protein
• Need to protect
DNA in nucleus
Transcription: What
Information from a gene is
copied to produce each
protein.
DNA  mRNA Protein
Transcription: Where
• Nucleus of cell
Transcription: How
Stop! Check Your Understanding
Complete the DNA RNA chart
Initiation Begin at Promoter region
Elongation –
RNA polymerase adds
nucleotides through the
coding region
Termination – Ends at the
termination sequence.
mRNA is now complete
Transcription details
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Initiation: Promoter identifies region to be transcribed
Elongation - Coding region has information for mRNA
RNA polymerase adds nucleotides to mRNA
Termination - ends transcript
mRNA is “edited” before leaving nucleus
Transcription: How
• Transcription Complete
Transcription: What’s Next?
• The product is an mRNA copy of DNA information
to make protein
• After transcription is complete:
DNA – forms Hydrogen bonds and reforms double helix
mRNA is edited (remove introns, exons are to be
expressed)
mRNA leaves the nucleus and enters cytoplasm for
translation
Watch transcription in action (DNAi)
click “copying the code”
click putting it together
click Transcription
After viewing this WAY COOL movie,
click interactive and make your own
RNA.
• Transcribe a gene (DNAi)
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Please summarize the process of
transcription in your own words
• RNA polymerase transcribes a gene from DNA
by adding RNA nucleotides until it reaches a
termination sequence. The mRNA is edited to
remove introns before leaving through a
nuclear pore so that translation can happen in
the cytoplasm.