19 Genetic Engineering Flashcards
Define Recombinant DNA
DNA combined from different organisms
Define Genetic Engineering
Deliberate manipulation of the genetic material to modify specific characteristics of an organism and this may involves transferring a gene into an organism so that the gene can be expressed
Outline Principles of Genetic Engineering
1 Objective is to add a DNA into the organism to give a new characteristic
2 Restriction endonuclease is used to obtain gene
3 Use Reverse Transcriptase to obtain gene from mRNA
4 Same enzyme is used to cut a plasmid
5 Using DNA Ligase combine gene into plasmid/vector
6 Introduce recombinant plasmid/vector into bacterium
7 Clone/Multiply bacterium
8 Gene is expressed
Explain why a promotor has to be transferred into an organism as well as the desired gene
1 To allow transcription/gene expression
2 At the right time in sufficient quantities
3. To allow RNA polymerase to bind
Explain how gene expression can be confirmed
Marker genes can be inserted into the plasmid near the recombinant DNA, so that it is expressed. When the marker gene is expressed, fluorescent proteins are produced thus under UV light recombinant organisms in which the recombinant DNA was expressed will fluoresce
Outline the process of Polymerase Chain Reaction (PCR)
1 Objective is amplification of DNA/ production of large copies of DNA
2 from a small sample of DNA
3 At 95°C DNA is denatured/separated into two strands
4 Primers are added
5 At 50°C annealing takes place - Primers bind to single-stranded DNA
6 At 72°C complementary base-pairing occurs
7 Taq polymerase is used to replicate the template strand
8 Taq polymerase is heat stable
9 Whole process is repeated
Explain the role of Taq polymerase in PCR
1 Taq polymerase is heat-stable/works at high temperatures
2 Does not need replacing after each cycle
3 Overall process is much faster and efficient
Define genome
All the genetic material in an organism’s cell
Outline the process of Gel Electrophoresis
1 Phosphate groups in DNA are negatively charged
2 Move towards anode
3 Larger fragments move more slowly
4 Different gels provide different resistance
5 The gel contains a buffer to maintain a constant pH
Outline how microarrays are used in analysis of genomes
1 Obtain single stranded DNA
2 Label with fluorescent tags
3 Probes present in microarray
4 Each probe is specific to a gene
5 DNA hybridises with probes
6 Unhybridised DNA washed off
7 View under UV light
8 Fluorescence indicates presence of gene
Outline the benefits of using databases in bioinformatics
1 Large amount of genetic information stored (DNA sequences, genes)
2 Quick data access
3 Can be used to compare sequences
4 Can be used to discover new genes, nucleotides or amino acid sequences
Outline the procedure used for gene therapy treatment of a person with SCID
1 Objective is to increase number of stem cells in bone marrow
2 Obtain a viral vector containing normal healthy allele for ADA
3 Remove stem cells from patient
4 Mix stem cells with viral vector
5 Use radiotherapy to kill existing stem cells in bone marrow to create space for new recombinant stem cells
6 Stem cells injected into blood
7 Lymphocytes produce functioning ADA
Outline the social and ethical considerations of using genetic screening and gene therapy
1 Expensive
2 No need for regular injections
3 Cultural and Religious objections
4 Possible cure/better quality of life
5 May cause cancer
Outline the advantages of using gene editing
1 Gene editing is accurate and precise
2 No need to introduce new genes/ patients’ own gene can be edited
3 No need to introduce promoter
4 Less chances of immune response
Explain the advantages of using recombinant human proteins to treat diseases
1 Can be made in large quantities
2 Cheap to make
3 Doesn’t harm animals
4 No risk of disease transfer
5 Doesn’t cause immune response
