biotech Flashcards
exons
coding sequence of proteins but usually dispersed within introns
cloning
process of creating exact copy of biological unit
- defined sequence of dna
gene
specefic sequence of dna that should be unchanged when copied
reverse transcriptase
turn mrna back into dna
turns dna into pre-mrna then cellular factors cut out introns and splice exons togerher
4 stages of biotech
- ISOLATE gene from donor dna (chromkosome from b-pancreatic cell)
2.INSERT gene into suitable cloning vector (bacterial plasmid)
3.introduce VECTOR into an expression host (bacteria or virus transcribe into mrna to translate into human insulin)
4.use recombinant expression host to scale up and purify, formulate, QC
PCR
1.denaturation - reverse transcriptase to seperate dna strands
2.annealing - 2 strands cooled and joined together by primers
3. synthesis - dna polymerase works on both strands
4.now repeat for 2 dna strands and keep replicating 2-4-8-16 so on
cloning vector
small piece of dna taken from a a virus, a plasmid or cell of higher orgainism - into which a foreign dna fragment can be inserted for cloning
plasmid
small double stranded self replicating circular dna molecules, distinct from normal bacterial chromosone
process of cloning
- insert gene into cloning vector
- transfect chimeric vector into prokaryotic cell (e-coli) the transformed
3.screen transformed cells to ensure correct gene
how to transform cell
- make cell temporarily permeable (competent) so that it can be take up plasmid dna
- the stop permeability so it doesnt leak back out
acheived witch heatshock (treated with CaCl heated to 42C then 0C) or electrotransformation (shocked with 200-2000V for a few minutes)
expression system
determines what its used for
Therapeutic antobidy must have full biological functionality to be effective
expressiopn system must oerform all required post tranlational modifications so replicated protein resembles native protein.
protein processing
additional modification after proteins have been translated to become fully functional (eg when proteins are glycosylated)