Lab 2. Flashcards
(31 cards)
What is bacterial transformation?
The acquisition of extracellular DNA from the environment.
Can the DNA that is taken up by transformation be passed down to future generations?
Yes.
The DNA is functioning and heritable.
The DNA that is taken up by transformation is usually in what form?
It is usually a plasmid.
The introduction of specific plasmids into bacterial cells allows for what?
The amplification of DNA within the plasmid.
For certain genes to be expressed such as genes that code for antibiotic resistance.
To code for bacterial colonies that have the plasmid to become a certain colour.
What is a plasmid?
A small, circular, double-stranded DNA molecule that is found outside of the bacterial chromosome.
Can plasmids replicate independently?
Yes.
Will a plasmid integrate itself into the bacterial chromosome?
No.
What is a major advantage that plasmids can offer bacterial cells?
Antibiotic resistance.
What are plasmids often used as tools for?
To clone, transfer, and manipulate genes.
How many proteins can be encoded by the LAC operon?
3 different proteins.
How many pieces of RNA are needed to produce the 3 proteins from their respective genes on the LAC operon?
1 piece of RNA.
What is the LAC operon used for?
For metabolising lactose.
When will the LAC operon be activated?
Only in the presence of lactose.
What strain of E.coli was used in lab 2?
Lac Z-.
What is the function of the Ampr gene on the LAC operon?
To produce β-lactamase.
What is the function of β-lactamase?
It inactivates the antibiotic ampicillin.
What is the function of the lacZ gene?
It produces β‑galactosidase.
What is the function of β‑galactosidase?
It will cleave the sugar X-Gal and this will cause colonies that have taken up the plasmid to turn blue.
What plasmid was inserted into the LACZ- e coli cells in lab 2?
The P-GAL plasmid.
What genes are found on the P-GAL plasmid?
The AMPr gene.
The LAC-Z gene.
Can the LAC-Z gene be turned off on the P-GAL plasmid?
No.
This is because the represor protein can’t bind to the lacZ gene as there is no binding site.
What is a competent cell?
A state where bacterial cells can take up DNA and become genetically transformed.
What are 4 types of naturally competent bacteria?
Bacillus subtilis.
Haemophilus influenzae.
Neisseria gonorrhoeae.
Streptococcus pneumonaiae.
What must bacterial cells be treated with in order to become competent?
With solutions that contain the chloride salts of metal cations such as calcium, rubidium or magnesium.
