3.15 - Genetic Engineering with Plasmids in Bacteria Flashcards
1
Q
What are plasmids?
A
Plasmids are loose pieces of DNA that bacteria can pick up. They are gathered by the small loops that bacteria store their DNA in.
2
Q
What are plasmids used for?
A
Genetic engineering
3
Q
Does bacteria have restriction enzyme sites?
A
Yes they do.
4
Q
In bacteria, why is it usefull having a gene for antibiotic restistance?
genetics
A
- it prevents bacteria from being killed by antibiotics
- For genetic engineering: it helps seperate the bacteria that has taken the plasmid from bacteria that has not. Ie., when the bacteria is exposed to a virus, the ones with the plasmid will survive
5
Q
How are plasmids put together?
A
- Plasmids are extracted and exposed to a restriction enzyme
- The DNA carrying the desired gene is exposed to the same restriction enzyme
- Both are mixed together with DNA ligase in hopes of the sticky ends of both pieces joing together to create recombinant DNA. this is not always the case, as sometimes either the plasmid, the DNA, or both can stick back onto itself
- DNA ligase seals the ideal pieces together with the required phosphodiester bonds
6
Q
How are plasmids inserted into bacteria?
A
- transformations
- to increase the probability of this bacteria gaining the plasmids, short blasts of heat, and electricity can be used to distrupt the mebrane. This allows plasmids to slide through
7
Q
What are 2 ways to test for a sucessful transformation?
[of plasmids entering bacteria]
Genetis
A
- expose it to an antibiotic: the bacteria with the plasmid will live, while the one without it won’t survive
- green fluoresent protein: shinning a certain light will cause the bacteria with the plasmid to glow
