gene technology Flashcards
recombinant DNA technology
combining different organisms DNA
enable scientist to manipulate and alter genes to improve industrial processes and medical treatment
sequencing projects
reading the full genome of organisms
provides opportunity to screen DNA to identify potential medical problems
how can you create a DNA fragment
reverse transcription with reverse transcriptase
restriction endonucleases
gene machine
gene machine
creates DNA fragments using a computerised machine
reverse transcriptase
An enzyme that makes a cDNA single-stranded copies of DNA from mRNA
restriction endonucleases
enzymes that cut up DNA to create fragments
cut at specific recognition/ restriction sequence
results in sticky ends
in vivo cloning
creating DNA fragments using bacteria
involves restriction endonuclease enzymes
in vitro cloning
using PCR to create a large number of copies of a DNA fragment
uses of PCR
used widely in gene technology to make large numbers of copies of DNA fragments
describe the process of PCR
increase temperature to 95C to
break hydrogen bonds & split
DNA into single strands
temperature is decreased to 55C
so primers can attach
DNA polymerase joins
complementary nucleotides &
makes a new strand
temperature increased to 72C
(optimum for Taq DNA
polymerase
uses of genetic fingerprinting
Forensic science
medical diagnosis
plant/animal breeding
paternity tests
what is gel electrophoresis
separation of DNA samples using an electrial voltage
different lengths of DNA VNTRs are separated
why does the DNA move in gel electrophoresis
DNA is negatively charged and
moves towards the positive end
of the gel
the shorter the piece of DNA, the
faster and further it moves
what is genetic screening
testing DNA to identify the presence of alleles that can cause/ increase the risk of developing a disease
what is genetic counselling
a type of social work giving people advice and information following the screening of disease causing alleles
what is cDNA
complementary, single-stranded DNA strands
created by reverse transcriptase
what are the advantages of using the gene machine
very quick
accurate
create intron-free DNA
what are the advantages of using reverse transcription
creates intron-free cDNA
what are the advantages using restriction endonucleases
creates sticky ends on DNA to enable the DNA fragments to join with complementary base pairs
oligonucleotides
shorts DNA molecules
used in gene machine to create DNA fragments
sticky ends
exposed staggered ends of bases
palindromic base sequences created by restriction enzymes
palindromic sequence
sequences of bases that read the same forwards as they do backwards
blunt end
When a restriction enzyme cuts the DNA double-strand in the same position
There is no overhang of bases
what are the two methods to amplify DNA
in vivo
in vitro
promoter region
a sequence of DNA that is binding site for RNA polymerase to enable transcription to occur
terminator region
added at the end of the gene
It causes RNA polymerase to detach and stop transcription
to ensure one gene is copied into mRNA at a time
plasmid
a small loop of bacterial DNA
contain only a few genes
contains the genes for antibiotic resistance
recombinant plasmid
a small loop of bacterial DNA with the DNA from another organism inserted into it
transformation
The process of getting a plasmid to re-enter a bacterium
involves calcium ions and temperature shocking
how can transformed cells be identified
using marker genes
antibiotic resistance genes
genes coding for fluorescent proteins
genes coding for enzymes
what is a marker gene
genes on the plasmid used to identify which bacteria successfully took up the recombinant plasmid
DNA probe
short, single-stranded pieces of DNA
labelled radioactively or fluorescently so that they can be identified
DNA hybridisation
DNA is heated to separate the double helix into single strands
its then mixed with complementary sequences of single-stranded DNA
it’s then cooled so complementary strands will anneal
personalised medicine
screening for the presence of particular alleles
to select medicines and personalise health advice based on your genotype
VNTRs
variable number tandem repeats sequences of bases in introns
unique to each person
How can DNA samples be collected
from blood, body cells or hair follicles
how is DNA extracted from cells so that it can be examined
cell fractionation and ultracentrifugation
how is DNA digested in genetic fingerprinting
Restriction endonucleases are added to cut the DNA into smaller fragments
enzymes that cut close to the target VNTRs are added
Why can the genome not be easily translated into the proteome in complex organisms
due to the presence of non-coding DNA and regulatory genes
what is the role of DNA ligase in making recombinant DNA
used to stick the DNA fragment to create recombinant DNA
