Wednesday, September 5

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17.1 1. Draw the nontemplate strand of DNA for
the template shown below. Compare and contrast
its base sequence with the mRNA molecule. DNA
A C C A A A C C G A G T   mRNA U G G U U U G G
C U C A
2
17.1 1. Draw the nontemplate strand of DNA for
the template shown below. Compare and contrast
its base sequence with the mRNA molecule. DNA
A C C A A A C C G A G T T G G T T T G G C T C
A mRNA U G G U U U G G C U C A
3
17.1 1. Draw the nontemplate strand of DNA for
the template shown below. Compare and contrast
its base sequence with the mRNA molecule. DNA
A C C A A A C C G A G T T G G T T T G G C T C
A mRNA U G G U U U G G C U C A
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17.1 2. What protein product would you expect
from a poly-G mRNA that is 30 nucleotides
long? 5-GGGGGGGGGGGGGGGGGGGGGGGGGGGGGG-3
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17.1 2. What protein product would you expect
from a poly-G mRNA that is 30 nucleotides
long? 5-GGGGGGGGGGGGGGGGGGGGGGGGGGGGGG-3 Gly-G
ly-Gly-Gly-Gly-Gly-Gly-Gly-Gly-Gly
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17.2 1. Compare and contrast the functioning of
DNA polymerase and RNA polymerase.
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DNA polymerase
RNA polymerase
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• DNA polymerase
• Assembles chains from monomers

• RNA polymerase
• Assembles chains from monomers

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• DNA polymerase
• Assembles chains from monomers
• Complementary base pairing

• RNA polymerase
• Assembles chains from monomers
• Complementary base pairing

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• DNA polymerase
• Assembles chains from monomers
• Complementary base pairing
• Reads 3?5
• Assembles 5 ?3

• RNA polymerase
• Assembles chains from monomers
• Complementary base pairing
• Reads 3?5
• Assembles 5 ?3

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• DNA polymerase
• Needs a primer

• RNA polymerase
• Can start from scratch

12

• DNA polymerase
• Needs a primer to start
• Uses A, T, G C
• Uses nucleotides containing deoxyribose

• RNA polymerase
• Can start from scratch
• Uses A, U, G C
• Uses nucleotides containing ribose

13
17.2 2. Is the promoter at the upstream or
downstream end of a transcription unit?
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17.2 2. Is the promoter at the upstream or
downstream end of a transcription unit? Upstream
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17.2 3. In a prokaryote, how does RNA polymerase
know where to start transcribing a gene? In a
eukaryote?
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17.2 3. In a prokaryote, how does RNA polymerase
know where to start transcribing a gene? In a
eukaryote? Prokaryote RNA polymerase
recognizes promoter Eukaryote Transcription
factors mediate binding
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17.2 4. How is the primary transcript produced
by a prokaryotic cell different from that
produced by a eukaryotic cell?
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17.2 4. How is the primary transcript produced
by a prokaryotic cell different from that
produced by a eukaryotic cell? Prokaryote
used immediately as mRNA Eukaryote Must be
modified before being used as mRNA
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17.3 1. How does the alteration of the 5 and 3
ends of pre-mRNA affect the mRNA that exists in
the nucleus?
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• 17.3
• 1.
• How does the alteration of the 5 and 3 ends of
  pre-mRNA affect the mRNA that exists in the
  nucleus?
• Facilitates transportation
• Prevents degradation
• Facilitates ribosomal attachment

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17.3 2. Describe the role of snRNPs in RNA
splicing.
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• 17.3
• 2.
• Describe the role of snRNPs in RNA splicing.
• Joins with other proteins to form spliceosomes.
• Removes introns, splices exons together.

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17.3 3. How can alternative RNA splicing
generate a greater number of polypeptide products
than there are genes?
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17.3 3. How can alternative RNA splicing
generate a greater number of polypeptide products
than there are genes? THE CAT ATE THE RBAT
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17.3 3. How can alternative RNA splicing
generate a greater number of polypeptide products
than there are genes? THE CAT ATE THE RBAT
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17.3 3. How can alternative RNA splicing
generate a greater number of polypeptide products
than there are genes? THE CAT ATE THE RBAT
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17.4 1. Which two processes ensure that the
correct amino acid is added to a growing
polypeptide chain?
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• 17.4
• 1.
• Which two processes ensure that the correct amino
  acid is added to a growing polypeptide chain?
• Aminoacyl-tRNA synthase
• tRNA codon

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17.4 2. Describe how the formation of
polyribosomes can benefit the cell.
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17.4 2. Describe how the formation of
polyribosomes can benefit the cell. Multiple
copies of a protein in a short time.
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17.4 3. Describe how a polypeptide to be
secreted is transported to the endomembrane
system.
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• 17.4
• 3.
• Describe how a polypeptide to be secreted is
  transported to the endomembrane system.
• Signal peptide is recognized by SRP.
• SPR brings polypeptide to ER lumen.

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17.5 1. Describe three properties of RNA that
allow it to perform diverse roles in the cell.
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• 17.5
• 1.
• Describe three properties of RNA that allow it
  to perform diverse roles in the cell.
• Hydrogen bonds with DNA or RNA
• Specific 3-D shape
• Catalize chemical reactions.

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17.6 1. In figure 17.22 (orange book and green
book) number the RNA polymerases in order of
their initiation of transcription. Then number
each mRNAs ribosomes in order of their
initiation of translation.
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17.6 2. Would the arrangement shown in Figure
17.22 be found in a eukaryotic cell? Explain.
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17.7 1. What happens when one nucleotide pair is
lost from the middle of the coding sequence of a
gene?
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• 17.7
• 1.
• What happens when one nucleotide pair is lost
  from the middle of the coding sequence of a gene?
  
• Frame shift mutation
• Nonfunctional protein

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17.7 2. The template strand of a gene contains
the sequence 3-TACTTGTCCGATATC-5. Draw a
double strand of DNA and the resulting strand of
mRNA, labeling all 5 and 3 ends. Determine the
amino acid sequence. Then show the same after a
mutation changes the template DNA sequence to
3-TACTTGTCCAATATC-5. What is the effect on the
amino acid sequence?
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17.7 2. Template strand 3-TACTTGTCCGATATC-5 Dr
aw a double strand of DNA.
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17.7 2. Double strand 3-TACTTGTCCGATATC-5 5-AT
GAACAGGCTATAG-3 Draw the resulting strand of
mRNA, labeling all 5 and 3 ends
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17.7 2. Double strand 3-TACTTGTCCGATATC-5 5-AT
GAACAGGCTATAG-3 mRNA 5-AUGAACAGGCUAUAG-3
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17.7 2. mRNA 5-AUGAACAGGCUAUAG-3 Determine
the amino acid sequence.
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17.7 2. mRNA AUG AAC AGG CUA UAG Determine the
amino acid sequence.
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17.7 2. mRNA AUG AAC AGG CUA UAG Polypeptide
Met-Asn-Arg-Leu
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17.7 2. Then show the same after a mutation
changes the template DNA sequence to
3-TACTTGTCCAATATC-5.
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17.7 2. Template strand 3-TACTTGTCCAATATC-5 Dr
aw a double strand of DNA.
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17.7 2. Double strand 3-TACTTGTCCAATATC-5 5-AT
GAACAGGTTATAG-3 Draw the resulting strand of
mRNA, labeling all 5 and 3 ends
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17.7 2. Double strand 3-TACTTGTCCAATATC-5 5-AT
GAACAGGTTATAG-3 mRNA 5-AUGAACAGGUUAUAG-3
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17.7 2. mRNA 5-AUGAACAGGUUAUAG-3 Determine
the amino acid sequence.
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17.7 2. mRNA AUG AAC AGG UUA UAG Determine the
amino acid sequence.
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17.7 2. mRNA AUG AAC AGG UUA UAG Polypeptide
Met-Asn-Arg-Leu
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17.7 2. mRNA AUG AAC AGG UUA UAG Polypeptide
Met-Asn-Arg-Leu The resulting polypeptide is
the same. .