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Figure 14.1
Figure 14.4a-2
mRNA
DNATRANSCRIPTION
TRANSLATION
Polypeptide
Ribosome
(a) Bacterial cell
Figure 14.4b-3
Nuclearenvelope
Pre-mRNA
mRNA
DNA
RNA PROCESSING
TRANSCRIPTION
TRANSLATION
Polypeptide
Ribosome
(b) Eukaryotic cell
Figure 14.5
DNAtemplatestrand
Protein
mRNA
3
Trp
TRANSCRIPTION
TRANSLATION
Amino acid
Codon
5
35
3
5
Phe Gly Ser
GU G U UU G G UC C A
CA C A AA C C AG G T
GT G T TT G G TC C A
Figure 14.6
UUU
Second mRNA base
UUC
UUA
UUG
UCU
UCC
UCA
UCG
UAU
UAC
UAA
UAG
UGU
UGC
UGA
UGG
CUU
CUC
CUA
CUG
CCU
CCC
CCA
CCG
CAU
CAC
CAA
CAG
CGU
CGC
CGA
CGG
AUU
AUC
AUA
AUG
ACU
ACC
ACA
ACG
AAU
AAC
AAA
AAG
AGU
AGC
AGA
AGG
GUU
GUC
GUA
GUG
GCU
GCC
GCA
GCG
GAU
GAC
GAA
GAG
GGU
GGC
GGA
GGG
Fir
st m
RN
A b
ase
(5
en
d o
f co
do
n)
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
U C A G
Phe
Leu
Ser
Tyr Cys
Trp
Met orstart
Stop
Stop Stop
Arg
Gln
His
ProLeu
Val Ala
Asp
Glu
Gly
IIeThr
Lys
Asn
Arg
Ser
Th
ird
mR
NA
bas
e (
3 e
nd
of
cod
on
)
Figure 14.7
(a) Tobacco plant expressinga firefly gene
(b) Pig expressing a jellyfishgene
Figure 14.8-3Transcription unit
RNA polymerase
Promoter
Template strand of DNA
Start point
Termination
Completed RNA transcript
RNA transcript
UnwoundDNA
RewoundDNA
RNA transcript
Direction oftranscription(“downstream”)
Initiation
Elongation
35
35
35 3
5
35
35
35
35
35
35
3
2
1
Figure 14.10
Nontemplate strand of DNA
Direction of transcription
RNA polymerase
3
53
5
RNA nucleotides
Template strand of DNA
Newly made RNA
3 end
5
UC
U
G
A
A
A
A
AA
A
AA
A
T T T
TT
T
T
CC
C
CCC C
G
GG
U
Figure 14.12
Introns cut out andexons spliced together
31–104
5 Cap
5 UTR 3 UTR
Poly-A tail
Codingsegment
1–146
AAUAAA
105– 146
5 Cap Poly-A tail
1–30
mRNA
Pre-mRNA
Intron Intron
Figure 14.UN04
DNA
mRNA
Ribosome
Polypeptide
TRANSLATION
TRANSCRIPTION
Figure 14.14
5
tRNA
Polypeptide
Ribosome
Anticodon
mRNA
Codons 3
tRNA withamino acidattached
Amino acids
Gly
Trp
Phe
A A A
A C C
CC
G
U U U G G CU G G
Animation: Translation Introduction
Figure 14.19-3Amino endof polypeptide
mRNARibosome ready fornext aminoacyl tRNA P
site
P i
5
3E
GTP
Asite
GDP
Peptide bondformation
Codon recognition
Translocation
E
P A
E
P A
P i
GTP
GDP
E
P A
3
2
1
Figure 14.22a
Incomingribosomalsubunits
(a) Several ribosomes simultaneously translating onemRNA molecule
Start of mRNA(5 end)
End of mRNA(3 end)
Growingpolypeptides
Completedpolypeptide
Polyribosome
Figure 14.23
RNA polymerase
mRNA
0.25 m
DNA
Polyribosome
RNA polymerase DNA
Polyribosome
Direction oftranscription
Ribosome
mRNA (5 end)
Polypeptide(amino end)
Figure 14.26
mRNA
DNA template strand
StopProtein Phe GlyMet Lys
A G3 T CC 5T T T TA A A AC C
5 3TA A A A AT T T TG G G G C
U5 3G CA U U G GGA A A AU U
Wild type
Phe GlyMet Lys
A A3 T CC 5T T T TA A A AC C
5 3TA A A A AT T T TG G G G T
U5 3G UA U U G GGA A A AU U
Phe SerMet Lys
A G3 T CC 5T T T TA A A AC T
5 3TA A A A AT T T TG G A G C
U5 3G CA U U A GGA A A AU U
Met
A C3 T CT 5A T A TC A A GC A
5 3TA T A T AG T T CG A T G G
U5 3G GA G U U GAU A U AU U
Leu AlaMet Lys
A A3 T GC 5T T T
A
A A C TC C
5 3TA A A AGT T AG G G C T
U5 3G UA U G G GGA A A
U
U A
GlyMet Phe
A T3 T TA 5A A
T T
C C G
C
C A
5 3TA T T
A
A
G G C
T
G T T A A
U5 3G AA G C U AUU U
A G
G
A
Met
A G3 T CC 5A T T TA A A AC C
5 3TA T A A AT T T TG G G G C
U5 3G UA U U G GGU A A AU U
Stop Stop
Stop
Stop
Stop
A instead of G
Silent (no effect on amino acid sequence)
(a) Nucleotide-pair substitution
U instead of C
T instead of C
Missense
A instead of G
A instead of T
Nonsense
U instead of A
Extra A
Frameshift causing immediate nonsense(1 nucleotide-pair insertion)
(b) Nucleotide-pair insertion or deletion
Extra U
Frameshift causing extensive missense(1 nucleotide-pair deletion)
missing
missing
missing
missing
No frameshift, but one amino acid missing(3 nucleotide-pair deletion)
Animation: Protein Synthesis
Figure 15.2
Regulationof geneexpression
Precursor
trpE gene
(a) Regulation of enzyme activity
Feedbackinhibition
Enzyme 1
Enzyme 2
Enzyme 3
Tryptophan
(b) Regulation of enzyme production
trpD gene
trpC gene
trpB gene
trpA gene
Operon: Genes that code for similar things are grouped together with a regulatory gene that controls their transcription
Figure 15.3a
(a) Tryptophan absent, repressor inactive, operon on
Protein
Inactiverepressor
mRNA
5
3
E D C B A
Regulatorygene
RNApolymerase
Genes that code for enzymes that make tryptophan
Operator
mRNA 5
trpE trpD trpC trpB trpAtrpR
Repressible operon: Tryptophan
Figure 15.3b
DNA
mRNA
Protein Activerepressor
No RNAmade
Tryptophan(corepressor)
(b) Tryptophan present, repressor active, operon off
What happens when tryptophan is present?Don‘t need to make tryptophan-building enzymes!
Figure 15.4b
IacZ IacY IacAIacI
lac operon
Permease Transacetylase-Galactosidase
mRNA
Protein
RNA polymerase
mRNA 53
5
Inactiverepressor
Allolactose(inducer)
(b) Lactose present, repressor inactive, operon on
Inducible operon: Lactose
Figure 15.4a
DNA
PromoterOperator
Regulatorygene
NoRNAmade
IacZlacI
mRNA RNApolymerase
3
5
ActiverepressorProtein
(a) Lactose absent, repressor active, operon off
Figure 15.10-3
DNA
EnhancerDistal controlelement
Activators PromoterGene
TATA box
DNA-bendingprotein
Group of mediator proteins
General transcriptionfactors
RNApolymerase II
RNApolymerase II
RNA synthesisTranscriptioninitiation complex
Figure 15.11Albumin gene
Crystallin gene
Promoter
Promoter
(b) LENS CELL NUCLEUS
Availableactivators
Albumin genenot expressed
Crystallin geneexpressed
Crystallin genenot expressed
Albumin geneexpressed
Availableactivators
(a) LIVER CELL NUCLEUS
Controlelements
Enhancer
Enhancer