Producing gene fragments Flashcards
What is Recombinant DNA
DNA of 2 different organisms that has been combined via isolation, cloning and transfer of DNA.
What do we refer an organism who has been subject to recombinant DNA practices?
Transgenic
OR
GMO (Genetically modified organism)
Why can DNA from one organism be accepted and function normally when transfered to another organism?
The genetic code is universal in all organisms.
What are the 5 stages of DNA technology gene transfer and cloning in order?
Isolation
Insertion
Transformation
Identification
Growth/Cloning
What are the methods on producing DNA fragments
Reverse transcriptase
Restriction endonucleases
Gene machine
Process of using reverse transcriptase to isolate gene fragements
Cell that produces protein is selected
mRNA of protein is extracted
Reverse transcriptase used to make DNA from RNA.
This DNA is known as complementary DNA (cDNA)
cDNA acts as a template and froms H bonds with complementary nucleotides, DNA polymerase froms phosphodiester bonds and forms the double stranded DNA
What is involved at the isolation stage?
Fragmentation of the DNA to isolate desired gene
What is involved at the insertion stage
DNA fragement inserted into a vector
What is involved in the transformation stage
DNA is transferred into a suitable hosts cell
What is involved in the identification stage
Host cells that have successfully taken up gene are identified with gene markers
What is involved in the cloning stage
Host cell population is increased
What does a restriction endonuclease do and what can they produce.
It cuts a DNA double strand at specific sequence of bases- recongition sites
This can produce both blunt ends and sticky ends - where the DNA is exposed and there are unpaired bases.
Process of using the gene machine.
Desired sequence of nucleotide bases is chosen
Desired sequence is fed into a computer
Sequence checked for biosafety and biosecutiry + international and ethical standards
Computer designs a series of small overlapping single strands called oligonucleotides
1 nucleotide is added at a time to these strands
Oligonucleotides are joined together to form the gene
Gene replicated using PCR
Genes are checked using standard sequencing techniques
Genes do not contain introns so splicing not required.
Benefits of recombinant DNA tech
Can produce large range of substances
Help fight pollution
GMC can increase yield and solve vitamin deficiency.
Risks of recombinant DNA tech
Cannot predict environmental impact
Gene may transfer from organism to organism
Bacterial resistance can be spread
Immoral.
