LGS A-Level OCR Biology - Unit 6 - Manipulating Genomes Part 3
This deck cycle includes denaturation, annealing of primers, and extension of new DNA strands by Taq polymerase.
Genetic engineering
Manipulating an organism's genome to achieve a desired outcome
Key Terms
Genetic engineering
Manipulating an organism's genome to achieve a desired outcome
Steps in genetic engineering
Obtaining the gene to be engineered
Placing the gene in a vector
Getting the gene into the recipient cell
Obtaining the gene to be engineered
Restriction enzyme looking for palindromic DNA, detected by gene probe (leaves sticky ends)
Isolating mRNA rom the gene and using reverse tra...
Placing the gene in a vector
Plasmid
Virus - inserted into a virus, then uses its usual mechanis of infecting cells by inserting its DNA (adenovirus, retrovirus, bacterip...
Ti-plasmid
Soil bacterium infects plants by inserting the Ti-plasmid DNA into the plant genome
Useful for genetic engineering of plants
Liposome
DNA is wrapped in a lipid molecule which can pass the lipid membrane by diffusion
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
Genetic engineering | Manipulating an organism's genome to achieve a desired outcome |
Steps in genetic engineering | Obtaining the gene to be engineered Placing the gene in a vector Getting the gene into the recipient cell |
Obtaining the gene to be engineered | Restriction enzyme looking for palindromic DNA, detected by gene probe (leaves sticky ends) Isolating mRNA rom the gene and using reverse transcription Synthetic sequencing - automated polynucleotide sequncer |
Placing the gene in a vector | Plasmid Virus - inserted into a virus, then uses its usual mechanis of infecting cells by inserting its DNA (adenovirus, retrovirus, bacteriphage) Ti-plasmid Liposome |
Ti-plasmid | Soil bacterium infects plants by inserting the Ti-plasmid DNA into the plant genome Useful for genetic engineering of plants |
Liposome | DNA is wrapped in a lipid molecule which can pass the lipid membrane by diffusion |
Vector in genetic engineering | Living/non-living factor that carries/inserts DNA into a host Has to contain reg. sequence of DNA to ensure the gene is transcribed (transformation) |
What's a plasmid | Small, circluar pice of DNA separate from the main bacterial chromosome |
Using plasmids in genetic engineering | Cut plamsids and target gene w/ SAME restriction enzyme to form complementary sticky ends Mix togther w/ DNA ligase - forms a recombinant plasmid |
Getting the gene into the recipient cell | Microinjection - injecting the plasmid Heat shock w/ calcium salts Electroporation Electrofusion |
Heat shock w/ calcium salts | Reducing the temp to freezing and rapidly increasing to 40 degrees - increases permeability Ca^2+ surrounds DNA (-ve), reduces repulsion, increases permeabilty Used in GM E.coli |
Electroporation | Small electric current is applied to bacteria | Makes membranes v. porous so plasmids move into the cell |
Electrofusion | Electric currents applied to membranes of 2 diff cells. Fuses cell and nuclear membrane to form a hybrid/polypoid Used to produce GM plants |
Purpose of replica plating | Identify the transformed or transgenic bacteria cells |
3 possible outcomes of genetic engineering | BC may not take up plasmid (heat shock failure) BC takes up non-recombinant plasmid (R enzymes fail ) Bc takes up recombinant plasmid |
Process of replica plating | Non recombinant DNA containing 2 marker genes has a gene inserted in the middle of the tetracycline resistant gene Grows bacteria on ampicillin agar - identifies whether bacteria has a plasmid Grown on tetracycline - only non-recombinant grow but Uses stamp |
Producing human insulin | Isolated using mRNA from beta cells then manufactured w/ reverse transcriptase Amplified and inserted into a bacterial plasmid w/ DNA ligase Identified by marker genes and then grown in fermenter (continuous culture) |
Marker genes | Identifies whther or not plasmids has been taken up |
Why do bacteria take up plasmds | Reproduce asexually - no genetic variation | Taking up plasmids from surroundings increases genetic variation, allows selection and evolution |
Somatic cell therapy | Body cells are target of gene therapy esp spp tissues Treatment is short lived and must be repeated regularly Involves ev vivo techniques -spp cells must be removed from the body, treated and replaced Liposomes are often used as a vector |