Post on 19-Dec-2015
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Microbial GeneticsMicrobial Genetics
I. Structure and function of DNA and genesI. Structure and function of DNA and genes
II. Gene expression in bacteriaII. Gene expression in bacteria
III. Mutation and variationIII. Mutation and variation
IV. Horizontal gene transfer in bacteriaIV. Horizontal gene transfer in bacteria
Nucleotides of __________________ ___________ (RNA)Nucleotides of __________________ ___________ (RNA)
Nucleotides of ____________________ Acid (DNA)Nucleotides of ____________________ Acid (DNA)
Note the numbering of the carbon atomsNote the numbering of the carbon atoms
“Growth” (__________________________) of a single DNA strand
“Growth” (__________________________) of a single DNA strand
5’5’
5’5’
3’3’
3’3’
3’3’
5’5’
Note: this is __________Note: this is __________ But RNA also But RNA also polymerizes like thispolymerizes like this
“_____________” arrangement of the two strands of a DNA molecule“_____________” arrangement of the two strands of a DNA molecule
5’ end5’ end
5’ end5’ end
3’ end3’ end
3’ end3’ end
The ‘base’ component of a nucleotide -- ________________
The ‘base’ component of a nucleotide -- ________________
AdenineAdenineAA
GuanineGuanineGG
The ‘base’ component of a nucleotide -- _________________
The ‘base’ component of a nucleotide -- _________________
CytosineCytosineCC
ThymineThymineTT
UraciUracillUU
Note that this is Note that this is riboseribose. What would deoxyadenosine . What would deoxyadenosine triphosphate (dATP) look like?triphosphate (dATP) look like?
or or ______________
The amount of adenine = the amount of ___________ The amount of adenine = the amount of ___________ and the amount of cytosine = the amount of and the amount of cytosine = the amount of ____________ in a cell____________ in a cell
DNA Secondary StructureDNA Secondary Structure
See text, Fig. 9.4See text, Fig. 9.4
Overview
DNA replicationDNA replication
Replication of the bacterial ________________Replication of the bacterial ________________
DNA Replication -- First StepsDNA Replication -- First Steps
DNA Replication -- First Steps (cont)DNA Replication -- First Steps (cont)
DNA structure and replicationDNA structure and replication
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are needed to see this picture.
Flow of genetic information in cells
Information processing in _____________Information processing in _____________
Information processing in _____________Information processing in _____________
Text, Fig. 9.18
Promoter regionPromoter region -- -- where where RNA polymeraseRNA polymerase binds binds
to initiate _____________________to initiate _____________________
One gene ---> one _______________One gene ---> one _______________
DNA Transcription
DNA Transcription
Transcription Animation
http://www.microbelibrary.org/FactSheet.asp?http://www.microbelibrary.org/FactSheet.asp?SubmissionID=378SubmissionID=378
Text, Fig. 9.13
Text, Fig. 9.13
Text, Table 9.3
The RibosomeThe Ribosome
A ribosome's true colors. (Top) The large subunit of the ribosome seen from the viewpoint of the small subunit, with proteins in purple, 23S rRNA in orange and white, 5S rRNA (at the top) in burgundy and white, and A-site tRNA (green) and P-site tRNA (red) docked according to (5).
(Bottom) The peptidyl transfer mechanism catalyzed by RNA
Translation: tRNATranslation: tRNA
________________ RNA (tRNA)________________ RNA (tRNA)
Prokaryotic TranslationProkaryotic Translation
AnimationAnimation
http://www.microbelibrary.org/FactSheet.asp?http://www.microbelibrary.org/FactSheet.asp?SubmissionID=379SubmissionID=379
Translation: the ribosomeTranslation: the ribosome
Translation: _______________Translation: _______________
Translation: Elongation (cont.)Translation: Elongation (cont.)
Translation: Elongation (cont.)
TranslationTranslation
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Text, Fig. 9.17
Replication problemReplication problem
Give the sequence of the strand replicated from the following Give the sequence of the strand replicated from the following strand:strand:
5’- GTT ATT CCC GTA ATC GGC TAG - 3’5’- GTT ATT CCC GTA ATC GGC TAG - 3’
Answer:Answer:
3’- __________________________________ - 5’3’- __________________________________ - 5’
Which direction relative to the original strand, left or right, would Which direction relative to the original strand, left or right, would the polymerase move as it makes this strand?the polymerase move as it makes this strand?
Answer: _____________Answer: _____________
Transcription ProblemTranscription Problem
AAssume that the strand just produced is the ssume that the strand just produced is the sense strandsense strand (the strand encoding the mRNA):(the strand encoding the mRNA):
3’- CAA TAA GGG CAT TAG CCG ATC - 5’3’- CAA TAA GGG CAT TAG CCG ATC - 5’
What would be the sequence of the mRNA transcript of this portion of the gene? Be sure and include 5’-3’ orientation.
Answer:
____________________________________
Translation problemTranslation problemTranslate your transcript using the following codon tableTranslate your transcript using the following codon table
5’- GUU AUU CCC GUA AUC GGC UAG - 3’
Answer:
____ ____ ____ ____ ____ ____ ____
ProblemProblemHere is a portion of the sense strand of a gene:
5’ – T A C C G A C C T T T G A G A A C T T G A – 3’
1) What would be the sequence of the strand which is replicated from this strand (be sure to note the 5’-3’ orientation of the strand)?
2) Which direction would the DNA polymerase move as it replicates this (sense) strand:
a. <---------- Left
b. ----------> Right
3) What would be the sequence of the mRNA transcript of this portion of the gene (include orientation)?
4) Translate using the codon table.4) Translate using the codon table.