Moodle Chapters 18-20.pptx

8/10/2019 Moodle Chapters 18-20.pptx

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Fig. 17-UN1

Transcription unit

Promoter

RNA transcript

RNA polymerase

Template strandof DNA

5

5 5 3

3 3


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Fig. 18-6a

DNA

Signal

Gene

NUCLEUS

Chromatin modification

Chromatin

Gene availablefor transcription

Exon

Intron

Tail

RNA

Cap

RNA processing

Primary transcript

mRNA in nucleus

Transport to cytoplasm

CYTOPLASM

Transcription


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Fig. 18-6b

mRNA in cytoplasm

Translation

CYTOPLASM

Degradationof mRNA

Protein processing

Polypeptide

Active protein

Cellular function

Transport to cellulardestination

Degradationof protein


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Fig. 18-18

Antenna

MutantWild type

Eye

Leg


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Fig. 18-3a

Polypeptide subunits that make upenzymes for tryptophan synthesis

(a) Tryptophan absent, repressor inactive, operon on

DNA

mRNA 5

Protein Inactiverepressor

RNApolymerase

Regulatory

gene

Promoter Promoter

t rp operon

Genes of operon

Operator

Stop codonStart codonmRNA

t rpA

5

3

t rpR t rpE t rpD t rpC t rpB

ABCDE


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Fig. 18-3b-1

(b) Tryptophan present, repressor active, operon off

Tryptophan(corepressor)

No RNA made

Activerepressor

mRNA

Protein

DNA


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Fig. 18-3b-2

(b) Tryptophan present, repressor active, operon off

Tryptophan(corepressor)

No RNA made

Activerepressor

mRNA

Protein

DNA


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Fig. 18-4a

(a) Lactose absent, repressor active, operon off

DNA

ProteinActiverepressor

RNApolymerase

Regulatorygene

Promoter

Operator

mRNA5

3

NoRNAmade

lac I lacZ


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Fig. 18-4b

(b) Lactose present, repressor inactive, operon on

mRNA

Protein

DNA

mRNA 5

Inactiverepressor

Allolactose(inducer)

5

3

RNApolymerase

Permease Transacetylase

lac operon

-Galactosidase

lacY lacZ lacAlac I


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Fig. 18-8-1

Enhancer(distal control elements)

Proximalcontrol elements

Poly-A signalsequence

Terminationregion

DownstreamPromoterUpstream

DNAExonExon ExonIntron Intron


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Fig. 18-8-2




Terminationregion


DNA

Exon Exon ExonIntronIntronCleaved 3 endof primarytranscript

Primary RNAtranscript

Poly-Asignal

Transcription

5

ExonExon ExonIntron Intron


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Fig. 18-8-3




Terminationregion


DNAExonExon ExonIntron Intron

Exon Exon ExonIntronIntronCleaved 3 endof primarytranscript

Primary RNAtranscript

Poly-Asignal

Transcription

5

RNA processing

Intron RNA

Coding segment

mRNA

5 Cap 5 UTRStart

codonStop

codon 3 UTR Poly-Atail

3

Fi 19 1


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Fig. 19-1

0.5 m

Fig 19 3


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Fig. 19-3

RNA

Capsomere

Capsomereof capsid

DNA

Glycoprotein 18 250 nm 70 90 nm (diameter)

Glycoproteins

80 200 nm (diameter) 80 225 nm

Membranousenvelope RNA

Capsid

Head DNA

Tailsheath

Tailfiber

50 nm 50 nm 50 nm 20 nm

(a) Tobacco mosaicvirus

(b) Adenoviruses (c) Influenza viruses (d) Bacteriophage T4

Fig 19 4


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Transcriptionand manufactureof capsid proteins

Self-assembly ofnew virus particlesand their exit from

the cell

Entry anduncoating

Fig. 19-4VIRUS 1

2

3

DNA

Capsid

4

Replication

HOST CELL

Viral DNA

mRNA

Capsidproteins

Viral DNA

Fig 19 6


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Fig. 19-6

PhageDNA

Phage

The phage injects its DNA.

Bacterialchromosome

Phage DNAcircularizes.

Daughter cellwith prophage

Occasionally, a prophageexits the bacterialchromosome,initiating a lytic cycle.

Cell divisionsproducepopulation ofbacteria infectedwith the prophage.

The cell lyses, releasing phages.

Lytic cycle

Lytic cycleis induced or

Lysogenic cycleis entered

Lysogenic cycle

Prophage

The bacterium reproduces,copying the prophage andtransmitting it to daughter cells.

Phage DNA integrates intothe bacterial chromosome,becoming a prophage.

New phage DNA and proteinsare synthesized andassembled into phages.

T bl 19 1


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Table 19-1a

T bl 19 1b


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Table 19-1b

Fig 19-7


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Fig. 19 7

Capsid

RNA

Envelope (withglycoproteins)

Capsid and viral genomeenter the cell

HOST CELL

Viral genome (RNA)

Template

mRNA

ER

Glyco-proteins

Capsidproteins Copy of

genome (RNA)

New virus

Fig. 19-8a


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Fig. 19 8aGlycoprotein

Reversetranscriptase HIV

RNA (twoidenticalstrands)

Capsid

Viral envelope

HOST CELL

Reversetranscriptase

Viral RNA

RNA-DNAhybrid

DNA

NUCLEUSProvirus

ChromosomalDNA

RNA genomefor thenext viralgeneration

mRNA

New virus

Fig. 19-8b


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Fig. 19 8b

HIVMembrane ofwhite blood cell

HIV entering a cell

0.25 m

New HIV leaving a cell


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Fig. 20-18


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TECHNIQUE

Mammarycell donor

RESULTS

Surrogatemother

Nucleus frommammary cell

Culturedmammary cells

Implanted

in uterusof a thirdsheep

Early embryo

Nucleusremoved

Egg celldonor

Embryonicdevelopment Lamb (Dolly)

genetically identical to

mammary cell donor

Egg cellfrom ovary

Cells fused

Grown inculture

1

33

4

5

6

2


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Documents

Moodle Chapters 18-20.pptx