MCAT Biotechnology Flashcards
What is recombinant DNA?
DNA that comes from two different sources.
Describe DNA cloning
DNA cloning is when a gene of interest is incorporated into a plasmid where it can be used to make many copies or be introduced into a organism.
- A restriction enzyme is an enzyme that cuts the gene of interest and plasmid, producing sticky ends, this allows the gene of interest to be incorporated into the plasmid.
DNA libraries
Genomic libraries v. cDNA libraries (expression libraries)
DNA libraries are large collections of DNA sequences.
Genomic library is a library that contains introns and exons and cannot be used to make recombinant proteins or used in gene therapy.
cDNA libraries contain DNA sequences with just exons and so can be used to make recombinant proteins and used in gene therapy.
Polymerase chain reaction
Method to create large numbers of DNA segments using hybridization.
DNA sequencing
Method to reading DNA sequences.
dideoxynucleotides are added to the growing strand and stops it because it lacks a 3’- OH end. We can then separate them using gel electrophoresis.
Gene therapy
Method to fix genetic diseases by introducing a functional gene into a plasmid which then replaces the dysfunctional gene.
Transgenic mice
Mice who we have integrated a gene of interest into embryonic stem cells of the germ line.
Chimeras
organisms that contain cells from two different cell lineages.
Knockout mice
Mice whose genes we have silenced.
Jacob- Monad model
Model that states that bacterial expression happens through operons in which are clusters of genes that are transcribed as a single mRNA strand.
Operators can in inducible or repressible.
Inducible operons system
Under normal conditions the operon contains a repressor thus silencing transcription.
When these conditions change inducers pull the repressors from the operator.
Repressible systems of operons
Operon systems which are transcribed under normal conditions but when not under those conditions a corepressor binds to the repressor.
The binding of this complex to the operator site stops transcription.
