8.4 gene technologies Flashcards
What is recombinant DNA technology?
Extracting and transferring genes or fragments of DNA from a donor org to a recipitant org
What does the recipiant org become after recombinant DNA technology?
a genetically modified org
Why is recombinant DNA technology possible? (2 reasons)
- the genetic code is universal to all orgs
- transcription and translation mechanisms are mostly the same in all orgs
What are the 2 area of uses of recombinant DNA technology?
agriculture and medicine
What is an example of using recombinant DNA tech in medicine?
treatments for Type 1 diabetes:
- the insulin in the injections if from prokaryotes that have had human DNA transfered into them so that they can produce human insulin
What is an example of the use of recombinant DNA tech in agriculture?
genetic modification of animals and plants to acquire new characteristics
eg. disease-resistant crops and nutritional crops
What is donor DNA?
gene that is isolated for insertion
What is a vector?
a carrier:
plasmids carry DNA into the recipiant DNA
What are restriction endonucleases?
enzymes that cut DNA at specific restriction sites
What are DNA ligases?
enzymes that join sections of DNA together
What are sticky ends?
2 ends of ‘cut’ DNA segment that have unpaired bases
What is recombinant DNA?
DNA which is formed when fragments of foreign DNA are inserted into other sections of DNA
What is reverse transcriptase?
enzymes used to synthesise DNA from mRNA in specific cells
What is a clone?
a population of genetically identical cells or orgs
What are the 5-step processes of recombinant DNA tech?
- isolation
- insertion
- transformation
- identification
- culturing
What are the 3 different methods that are used to isolate desried genes?
restriction endonucleases
reverse transcriptase
gene machine
What 2 things need to be done before you isolate a desired gene?
- locate the gene - use a cell that naturally produced the desired protein
- identify the gene locus by using a gene probe
How does a gene probe identify a gene locus?
the probe has a specific seq of single-stranded DNA which is complimentary to the desired gene
it is labelled by using flouresence or a radioactive tracer
What type of org naturally produces restriction endonucleases and why?
bacteria as a defence mech against viral infection
How do restriction endonucleases cut double stranded DNA?
hydrolyse phosphodiester bonds
What are the 2 different ways that restriction endonucleases cut DNA ( the structures DNA forms after being cut)?
form blunt ends
or palindromic sticky ends = staggered cut
What does palindromic mean?
the DNA base sequences of the staggered sticky ends read the same forwards and backwards
Which type of restriction endonuclease cutting is more useful?
staggered sticky ends
Why are staggered sticky ends more useful?
they have unpaired DNA bases that can easily complimentary base pair to exposed bases on DNA in the recipiant org
easier to join DNA