Molecular Genetics & Biotechnology - Lecture Nineteen

Question 1

What are recombinant DNA technologies?

Answer 1

Joining bits of DNA together (sometimes from different species). These are then inserted into an organism to produce (or express) a useful protein

Question 2

Plasmids

Answer 2

(Usually) circular pieces of double stranded DNA
Replicate independently of the host’s chromosomal DNA
Common in bacteria, but also found in eukaryotes.
Provide a benefit to hosts, e.g. antibiotic resistance

Question 3

Key components of recombinant DNA plasmids - Origin of Replication (ORI)

Answer 3

Allows initiation of replication using host DNA polymerase - maintains copies of the plasmid

Question 4

Key components of recombinant DNA plasmids - Antibiotic Resistance Gene

Answer 4

Allows selection of cells containing plasmid

Question 5

Key components of recombinant DNA plasmids - Promoter

Answer 5

Drives expression of your favourite gene (e.g. insulin or GFP) in cells with appropriate transcription factor machinery

Question 6

Restriction enzymes

Answer 6

Critical to be able to cut and paste favourite genes into plasmids for use. Restriction. enzymes are normally found in bacteria

Question 7

Ligases

Answer 7

When the enzyme cuts the DNA, they have sticky ends but won’t stick back together until a DNA ligase enzyme has repaid the breakage

Question 8

Transformation

Answer 8

The transferring of plasmids into bacteria

Question 9

The catch when cloning eukaryotic genes for expression in prokaryotes

Answer 9

Prokaryotic genes don’t have introns or the machinery to process eukaryotic introns so they only use coding sequence