Plasmids Flashcards
What are some of the uses for genetic transformation?
- agriculture: coding for resistance against frost, pest, or spoilage
- Bioremediation: bacteria can be genetically transformed with genes enabling them to digest oil spills
- medicine: diseases caused by defective genes can be treated by gene therapy
T/F: all plasmids are vectors
false
What is a plasmid?
small, circular, double stranded, extrachromasomal elements found in some bacteria strains
since plasmids are closed circular double-stranded DNA molecules they are under…?
super helical tension and negative supercoiling
T/F: all plasmid forms have the same molecular weight.
true
What genes are encoded on plasmid DNA?
- genes for its own replication and propogation
- origins of replication
- gene for partitioning plasmids into each daughter cell during cell division
- genes that give advantages to their bacterial hosts.
what is a common plasmid advantage?
ampicillin resistance
What is a selectable marker?
A plasmid is coded for a specific thing ie antibiotic resistance and will kill off everything except that speicfic thing
what is a multiple cloning site?
requires the removal and addition of various restriction enzyme sites so a region on the plasmid would contain a number of unique restriction enzyme sites
what are regulatory signals
regulates expression of cloned genes
how do promoter sequences help plasmids?
allows expression (transcription) of gene cloned into plasmid
what is a pGLO plasmid?
green fluorescent protein gene in jellyfish
what is pGLO induced by?
the sugar arabinose
what is pGLO for?
ampicillin resistance
what is the process of gene cloning in bacteria?
- isolates the fragment of DNA containing the gene of interest
- fragment is inserted containing the gene to produce recombinant DNA molecule
- then introduce the recombinant DNA into host cell
- plate transformed bacteria so it can grow and form a colony
- colony then produces many new recombinant bacteria plasmids
how many times should a plasmid be cut?
1-2 since more will shred the DNA (even 2 is a lot)
What is transformation of plasmids?
insertion of free DNA into the cell
What is transduction of plasmids?
DNA containing virus is inserted into the bacteria cell
What is conjugation of plasmids?
plasmid is placed into donor cell which is then transferred into a secondary cell
what is the specialized limb in the conjugation of plasmids?
conjugation tube
What is the hypothesized reason for CaCl2 treatment?
creating pores and priming the cells
what is the heat-shock method?
incubate bacterial cells with cold solution of CaCl2 which makes pores adding the DNA to the cells and then the incubation heat shocks it
explain electroporation:
short current pulses create pores and the bacteria is washed with cold H2O to remove residual ions , DNA is added
what is lipofection?
DNA is encapsulated by a micelle and fused to a cell membrane
