Chapter 17 From Gene to Protein

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Chapter 17From Gene to Protein
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Chapter 17From Gene to Protein

• One gene, one protein

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Chapter 17From Gene to Protein

• One gene, one polypeptide

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Chapter 17From Gene to Protein

• One gene, one polypeptide
• A few genes have RNA
• as their final product.

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Chapter 17From Gene to Protein

• Transcription

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Chapter 17From Gene to Protein

• Transcription
• DNA ? mRNA

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Chapter 17From Gene to Protein

• Translation

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Chapter 17From Gene to Protein

• Translation
• mRNA ? polypeptide

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Chapter 17From Gene to Protein

• Codon

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Chapter 17From Gene to Protein

• Codon
• A three-letter word in the DNA alphabet (A, T,
  G, C) that spells the name of a specific amino
  acid.

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Chapter 17From Gene to Protein

• Anticodon

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Chapter 17From Gene to Protein

• Anticodon
• The complement to a codon.
• If the codon is ATG (or AUG), the anticodon is
  TAC (or UAC).

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• AT
• TA
• TA
• GC
• AT
• CG
• GC
• GC

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A
• G C
• A T
• C G
• G C
• GC

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A
• G C anticodon
• A T
• C G
• G C
• GC

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T AU
• G CG
• A TA
• C G
• G C
• GC

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A U
• G C G
• A T A
• C G
• G C
• GC

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A U
• G C G
• A T A
• C G
• G C
• GC

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A U
• G C G codon
• A T A
• C G
• G C
• GC

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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A U
  A
• G C G
  C
• A T A
  U
• C G
• G C
• GC

cystine
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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A U
  A
• G C G
  C
• A T A
  U
• C G anticodon
• G C
• GC

cystine
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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A U A
• G C G C
• A T A U
• C G
• G C
• GC

cystine
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Chapter 17From Gene to Protein

• DNA mRNA tRNA
• GC
• A T
• T A
• T A UA
• G C GC
• A T AU
• C G
• G C
• GC

cystine
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Chapter 17From Gene to Protein

• Anticodon wobble

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Chapter 17From Gene to Protein

• Anticodon wobble
• Some anticodons in tRNA
• are not completely specific.

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Transcription
promoter gene

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Transcription

• RNA polymerase

promoter gene

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Transcription

• RNA polymerase
• The enzyme that synthesizes RNA from a DNA
  template.

RNA polymerase
promoter gene

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Transcription

• Promoter

RNA polymerase
promoter gene

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Transcription

• Promoter
• Specific DNA sequence that marks the beginning of
  the gene.

RNA polymerase
promoter gene

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Transcription

• Transcription factor

RNA polymerase
promoter gene

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Transcription

• Transcription factor
• Protein that helps RNA polymerase recognize the
  promoter.

RNA polymerase transcription factor
promoter gene

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Transcription

• Transcription factor
• Protein that helps RNA polymerase recognize the
  promoter.

RNA polymerase transcription factor
promoter gene

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Transcription

• Transcription factor
• Protein that helps RNA polymerase recognize the
  promoter.

RNA polymerase transcription factor
promoter gene

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Transcription

• Transcription factor
• Protein that helps RNA polymerase recognize the
  promoter.

RNA polymerase transcription factor
promoter gene

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Transcription

• Transcription factor
• Protein that helps RNA polymerase recognize the
  promoter.

RNA polymerase transcription factor
promoter gene

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Transcription

• Transcription factor
• Protein that helps RNA polymerase recognize the
  promoter.

RNA polymerase transcription factor
promoter gene

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Transcription

• Initiation

RNA polymerase transcription factor
promoter gene

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Transcription

• Initiation
• RNA polymerase binds to promoter
• DNA unwinds
• Synthesis begins

RNA -
RNA polymerase transcription factor
promoter gene

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Transcription

• Elongation
• RNA polymerase binds to promoter
• DNA unwinds
• Synthesis begins

RNA ----
RNA polymerase transcription factor
promoter gene

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Transcription

• Elongation
• Polymerase moves 3?5 on DNA
• DNA unwinds
• RNA is made 5?3

RNA ------
RNA polymerase transcription factor
promoter gene

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Transcription

• Elongation
• Polymerase moves 3?5 on DNA
• DNA unwinds
• RNA is made 5?3

RNA ------
RNA polymerase transcription factor
promoter gene

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Transcription

• Termination

RNA ------
RNA polymerase transcription factor
promoter gene

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Transcription

• Termination
• RNA transcript is released
• Polymerase detaches from DNA

RNA ------
RNA polymerase transcription factor
promoter gene

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Transcription

• Termination
• RNA transcript is released
• Polymerase detaches from DNA

RNA ------
RNA polymerase transcription factor
promoter gene

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Transcription
RNA ------
RNA polymerase transcription factor
promoter gene

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RNA Processing
RNA ------
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RNA Processing
RNA transcript (pre-mRNA)
5hemomyoblahglobblahin3
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RNA Processing
RNA transcript (pre-mRNA) 5 cap 3 poly(A)
tail
5hemomyoblahglobblahin3
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RNA Processing
RNA transcript (pre-mRNA) 5 cap 3 poly(A)
tail
5hemomyoblahglobblahinAAAAAAA3
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RNA Processing
RNA transcript (pre-mRNA) Removal of
introns
5hemomyoblahglobblahinAAAAAAA3
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RNA Processing
RNA transcript (pre-mRNA) Removal of
introns
5hemomyoblahglobblahinAAAAAAA3
5hemomyoblahglobblahin3AAAAAAA
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RNA Processing
RNA transcript (pre-mRNA) Removal of
introns
5hemomyoglobblinAAAAAAA3
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RNA Processing
RNA transcript (pre-mRNA) Removal of
introns
5hemoglobinAAAAAAA3
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RNA Processing
RNA transcript (pre-mRNA) Removal of
introns
5hemoglobinAAAAAAA3 hemoglobin
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Alternate RNA Processing
RNA transcript (pre-mRNA)
5hemomyoblahglobblahinAAAAAAA3
Alternate processing
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Alternate RNA Processing
RNA transcript (pre-mRNA)
5hemomyoblahglobblahinAAAAAAA3
5hemomyoblahglobblahin3AAAAAAA
Alternate processing
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Alternate RNA Processing
RNA transcript (pre-mRNA)
5hemyobhglobbhinAAAAAAA3
Alternate processing
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Alternate RNA Processing
RNA transcript (pre-mRNA)
5myoglobinAAAAAAA3
Alternate processing
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Alternate RNA Processing
RNA transcript (pre-mRNA)
5myoglobinAAAAAAA3 myoglobin
Alternate processing
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RNA Processing

• Introns
• Exons

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RNA Processing

• Introns
• Noncoding regions of RNA.
• Exons
• Coding regions of RNA.

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RNA Processing

• Introns
• Noncoding regions of RNA.
• (They intrude.)
• Exons
• Coding regions of RNA.
• (Theyre expressed.)

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RNA Processing

• small nuclear ribonucleoproteins

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RNA Processing

• small nuclear ribonucleoproteins

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RNA Processing

• small nuclear ribonucleoproteins

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RNA Processing

• small nuclear ribonucleoproteins

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RNA Processing

• small nuclear ribonucleoproteins

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RNA Processing

• small nuclear ribonucleoproteins
• (snRNPs)

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RNA Processing

• small nuclear ribonucleoproteins
• (snRNPs)
• make up splicosomes

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RNA Processing

• small nuclear ribonucleoproteins
• (snRNPs)
• make up splicosomes
• which are enzymes

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RNA Processing

• small nuclear ribonucleoproteins
• (snRNPs)
• make up splicosomes
• which are enzymes
• that remove introns.

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Translation
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Translation

• Ribosomes

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Translation

• Ribosomes
• Made of RNA and protein
• Two subunits
• Two sites (A P) for tRNA binding
• One site (E) for tRNA release.

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Translation
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Translation

• Signal peptides

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Translation

• Signal peptides
• Bind to signal recognition particles.
• SRPs carry new polypeptides to specific
  locations.

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Translation

• Prokaryote vs. Eukaryote

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Translation

• Prokaryote vs. Eukaryote
• Translation
• can happen
• at the same
• time as trans-
• cription

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Translation

• Prokaryote vs. Eukaryote
• Translation Translation
• can happen happens after
• at the same processing.
• time as trans- --introns
• cription. --5 cap
• --poly-A tail.

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Mutations
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Mutations

• The cat ate the rat

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Mutations

• The cat ate the rat
• Point mutations

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Mutations

• The cat ate the rat
• Point mutations
• The cat ate the bat

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Mutations

• The cat ate the rat
• Point mutations
• The cat ate the bat
• Frame shift mutations

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Mutations

• The cat ate the rat
• Point mutations
• The cat ate the bat
• Frame shift mutations
• The cat tet her atP

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Transcription (Review)

• RNA polymerase
• Enzyme that makes RNA
• Promoter
• marks beginning of gene
• Transcription factor
• helps polymerase find promoter.

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Transcription (Review)

• Initiation
• polymerase binds, DNA unwinds
• Elongation
• 3?5 on DNA, 3?5
• Termination
• primary transcript is released.

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Transcription (Review)

• 5 cap
• Poly-A tail
• Splicosomes remove introns
• Alternate RNA processing.

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Translation (Review)

• Ribosomes
• Two subunits
• A, P, E sites
• Signal recognition particles.

.