chapter 13: biotech Flashcards
restriction enzymes
scissors for dna
recombinant dna
single molecules containing dna sequences from two or more organisms
gel electrophoresis
analysis/purification/organization by length of dna fragments
dna ligase
joins dna fragments
recognition sequence
aka restriction site
- specific series of bases where restriction enzymes cut the dna
- usually 4-6 base pairs long
- palindromes: same forward/backwards
sticky ends
able to form hydrogen bonds with complementary sequences
blunt ends
bad for joining
use for analysis for research
restriction digest
the process of using restriction enzymes in the lab to cut sample dna
knowledge from gel electrophoresis
- number of fragments
- sizes of fragments
- relative abundance of fragments
transformation/transfection
cloning recombinant dna by inserting if into host cell
transgenic cell/organism
used as host for recombinant dna
selectable marker genes
used so that only the transgenic cells grow
electroporation
electric shocks are used to open temporary pores in membrane that allow dna to enter
how dna becomes a part of the replicon
- inserted into host chromosome
- enters through a vector
plasmids
- small, circular dna molecules that replicate in prokaryotic cells
- used as transformation vectors
- often serve as selectable markers too
reporter gene
any gene whose expression is easily assayed
ex: selectable markers, glow in the dark gene
genomic library
collection of dna fragments that comprises the genome of an organism
cDNA library
- made of complementary dna
- a snapshot of transcription
knockout experiment
to knockout genes by inactivating them so that they cannot be transcribed/translated
homologous recombination
- a way of knocking out a gene
- reporter gene interrupts gene so that it no longer creates a functional gene
- recombinant plasmid is made and used to specify stem cells
- if recombination occurs, the inactive allele is replaced by an allele of the host cell
antisense RNA
binds to mrna and inhibits trnanslation
often used as drugs
RNA interference (RNAi)
- natural mechanism
- small interfering rnas (siRNA)
- gene knockdown
expression vectors
vectors with extra sequences for the transgene. can include:
- inducer promoter
- tissue specific promoter
- signal sequences
Advantages of recombinant dna tech
- ability to identify specific genes
- ability to introduce any gene from any organism into a plant/animal species
- ability to generate new organisms quickly
public concern over biotech
- its an unnatural interference with nature
- altered foods are unsafe to eat
- dangerous to environment
