topic 888 Flashcards
why can thee transfeered DNA be transcribed/ translated into proteins of tthe recipent
the genetic sequence is universal
so are the transcription and translation mechanism
what is recombinant DNA
the transfer of DNA fragments from one organism to another
what is used convert mRNA into cDNA
reverse transcriptase
how’s fragments of DNA made
- conversion of mRNA to cDNA using reverse transcriptase.
- using restriction enzymes to cut the fragments containing the desired gene from DNA
- creating a gene in a gene machine
how are fragments of DNA amplified
in vitro and in vivo techniques
what type of method is polymerase chain reaction (PCR)
in vitro
what does the process of using reverse trancriptase to obtain a DNA fragment include
mRNA which codes for the required protein is isolated
- DNA nucleotides bind to the mRNA
- reverse transcriptase uses mRNA to synthesise cDNA
what does cDNA stand for
complimentary DNA
what type of enzyme is used to cut a fragment containg the desired gene from DNA
restriction endonucleases
what is the role of restriction endonucleases
they recognise specific palindromic sequences of DNA. and they cut DNA at these places
what is meant by a palindromic sequence of DNA
the base pairs are read the same in opposite directions
where do restriction endonucleases cut at
at specific recognition sequences
what bonds do restriction endonucleases break
phosphodiester bonds
what is the active site of restriction endonucleases complimentary to
the shape of the recognition sequence
what do sticky ends do
they bind to a piece of DNA that has sticky ends which have a complimentary sequence
what enzyme binds to sticky ends together
ligase
how is a gene created in a gene machine
synthesis fragments of DNA from scratch witthout using an existing DNA template.
what are advantages of using mRNA to make DNA fragments rather than restriction enzymes
more mRNA in cell comparedd to DNA
bacteria cant remove introns
what is an example of an in vitro method
polymerase chain reaction
what is a promoter region
DNA sequences that tells RNA polymerase to start producing mRNA
what is a terminator region
tells RNA polymerase when to stop
what happens to the number of DNAA in PCR
it doubles
what is in the reaction mixture of a polymerase chain reaction
DNA sample
free nucleotides
primers
DNA polymerase
what are primers
are short pieces of DNA that are complentary to the bases at the start of the fragment
what is taq polymerase
a different version of DNA polymerase
at wwhat temperature are the hydrogen bonds broken
95 degrees
why is the DNA heated to 95 degrees
to break the hydrogen bonds
why is the mixture cooled
so that the primers can bind/anneal to the exposed bases
what temperature id the mixture cooled to
50-65 degrees
why is the reacttion mixture then reheated to 72 degrees
so that its thee optimum temperature for DNA polymerase
what is the role of DNA polymerase in PCR
it joins the adjacent nucleotides forming phosphodiester bonds
what is the optimum temperature of DNA polymerase
72 degrees
