DNA Fragmenting Flashcards
What does recombinant DNA technology involve?
The transfer of fragments of DNA from one organism species to to another.
State why transfer of DNA between organisms is possible.
Genetic code is universal
What are transgenic organisms?
An organism or cell whose genome has been altered by the introduction of one or more foreign DNA sequences from another species by artificial means. (Also known as GMOs)
As genetic code is universal, this can allow which process to happen in transgenic organisms?
Translation of transferred DNA
Name a protein produced in large volumes by recombinant DNA technology.
Insulin
Name the 5 stages of producing a protein by DNA technology.
- Isolation of DNA
- Insertion of DNA into vector
- Transfer of DNA to hosts
- Identification of hosts
- Growth/cloning of hosts
Which stage of producing proteins by DNA technology is DNA fragmenting?
1, isolation of DNA
What does c in cDNA stand for?
Complementary
Name the enzyme that converts mRNA to cDNA.
Reverse transcriptase
What are and what do restriction endonucleases do?
They are enzymes that cut the sugar phosphate backbone of DNA at a specific recognition or restriction site.
What is a primer?
A short strand of DNA synthesised to be complimentary to a sequence of nucleotide bases at the ‘3 end of the DNA.
What does mRNA act as when forming cDNA?
Why?
A template
The nucleotides used to make the cDNA are complimentary to the mRNA
Once the primer and DNA nucleotides are added to the medium containing cDNA, where will they move/line up?
How does this lead to production of the DNA strand? Name the enzyme used.
They would line up opposite the complementary bases on the cDNA strand.
This acts as the point of attachment for the DNA polymerase to begin to assemble the nucleotides to form the new strand.
Why are restriction enzymes used by bacteria and archaea?
For protection against phage viruses
How do restriction enzymes protect bacteria against viruses?
They cut DNA which prevents viruses from making copies of themselves.
Explain why b cells from the Islets of Langherans are used to synthesise insulin.
They produce large amounts of mRNA that codes for the protein which can be isolated and used to produce cDNA.
What are blunt ends and how are they formed?
Blunt ends are formed when restriction endonucleases make straight cuts through the DNA. This means that DNA fragments are straight.
What are sticky ends and how are they formed?
Sticky ends form when the restriction endonuclease cuts in a staggered fashion, leaving uneven cuts with bases exposed at either end of the molecule
What is a palindrome?
Base sequences that read opposite to each other.
What is a gene machine?
The use of bioinformatics to synthesise a specific gene
Why is the biosafety of genes checked before synthesising the gene?
Ethical reasons
What is ssDNA?
Single stranded DNA
What is an oligonucleotide?
A polynucleotide whose molecules contain a relatively small number of nucleotides.
Describe how oligonucleotides are joined together in a gene machine?
They are joined by DNA polymerase.
What type of section of DNA is not present in oligonucleotides?
Introns
