B6: Gene technologies Flashcards
what goes genetic engineering involve
taking copy of gene from one organism
+ inserting gene into DNA of another organism
to created genetically modified organism (GMO)
how were bacteria resistant to kanamycin antibiotic created
inserted a kanamycin resistance gene into a bacterial cell.
bacterial cell was then able to survive in the presence of the antibiotic.
process of genetically engineering bacterial cells 1.
useful gene cut
from DNA of one organism
using the enzyme restriction enzyme
what does the restricition enzyme do
break bonds between nucleotides
process of genetically engineering bacterial cells 2.
Restriction enzymes cut the DNA in a staggered way leaving short sections of single-stranded DNA
at each end of the gene.
These sections of single-stranded DNA are called sticky ends.
process of genetically engineering bacterial cells 3.
bacterial plasmid DNA is cut open using the same restriction enzyme
The cut ends of the plasmid also have sticky ends.
why is the same restriciton enzyme used
so sticky ends on plasmid will have
short sequence of bases
complementary to those on end of useful gene
process of genetically engineering bacterial cells 4.
- useful gene and the plasmid DNA are mixed
- the gene is inserted into the plasmid.
- Hydrogen bonds form between the complementary bases in the sticky ends of the plasmid and the useful gene.
process of genetically engineering bacterial cells 5.
enzyme DNA ligase is used to join the plasmid DNA and the useful gene together.
The ligase joins the end nucleotides of the useful gene to the end nucleotides of the plasmid.
define recombinant plasmid
It is a plasmid that has been altered and now has DNA from more than one source.
process of genetically engineering bacterial cells 6.
recombinant plasmid is then inserted into a bacterial cell. plasmid acts as a vector, carrying the gene into the bacterial cell.
process of genetically engineering bacterial cells 7.
bacterial cell is now a GMO.
can be cultured by cloning t
he cell can use the gene that has been inserted into it to make a protein.
describe how a GM plant is created
- recombinant Ti plasmid created by inserting useful gene ( step 1-5 )
- plasmid inserted into A.tumefaciens to create transgenic bacterial cell
3.plant cells grown in lab mixed with transgenic A.tumefaciens .
Ti plasmid carries useful gene into plant cell + inserts in plant chromosome
4.plant cell grown in culture in lab + develop into new plants. each GM plant able to produce protein coded for by useful gene. plant has new characterisitic
uses of GM plants
pest resistance- Bt cotton resistant to cotton bullworm
herbicide resistance - GM crops resistant to weedkillers
disease resistance - bananas modified to resist black sigatoka fungus
ability to produce nutrients to help malnutrition- increase in vitiamin tin golden rice
benefits + risks of GM in meical engineering
- GMO can be used to produce medicines
- med from GMO organisms allows medicines to be produced in larger quanitities
- proteins made by bacteria are human proteins= less likely side effects
- GMO only been used for short time, so long-term consewuences unknown
GMOs have been used in the development of vaccines.
aims to provide safer, cheaper vaccines for deadly diseases.
GM pigs are being developed with human-like organs.
helping to reduce the shortage of suitable donor organs.
concerns that the use of such organs could result in the spread of disease from pigs to humans.
Some people will object to the use of these organs for ethical reasons.
GM insects have been created to reduce the spread of certain diseases such as malaria.
genetically modified Anopheles mosquitoes
so more efficient immune response
when infected with the malarial parasite.
prevents the malarial parasite from being able to survive in the mosquito.
The GM mosquitoes can breed with wild mosquitoes, passing the gene for a more efficient immune response to their offspring.
Some people object to use of GMOs in this way as they may affect the success of wild populations of insects
Genetic modification of cells in the human body can be carried out using gene therapy techniques to provide possible cures for genetic diseases such as cystic fibrosis.
risks, e.g. if the therapeutic gene is not accurately inserted into a chromosome it can cause cancer. Cancer arises when the therapeutic gene is inserted too close to a cancer-causing gene and this gene is then switched on.
The therapeutic gene is inserted into the chromosome using a special type of virus and at the moment we are unable to control the position that it is inserted into a chromosome.
