B21 Flashcards
Bioinformatics
development of software and computing tools needed to analyse biological data
- develop algorithms, statistical tests, mathematical models to help understand
- studies generate data on DDNA sequences, protein sequences & relationship between genotype and phenotype
Computational biology
- uses data from bioinformatics to build theoretical models of biological systems
- the study of biology using computational techniques
- analyse biodata
- work out protein 3D structure
- help understand pathways e.g. gene regulation
- help identify genes linked to diseases etc.
DNA barcoding
Identify genome sections common to all species but varies between them & make comparisons
- Use cytochrome C oxidase
cytochrome C oxidase usage in DNA barcoding
- in mitochondrial DNA
- codes for respiration enzyme
- small = quick & cheap sequencing
- varies to give clear differences between species
Benefits of analysing genomes of pathogens
-fast & relatively cheap
- doctors find infection source
- doctors can identify antibiotic-resistant strands = prevent further resistance by only using antibiotic when needed
- track spread & transmission & plan suitable treatment
- track progress of an outbreak
- Identify useful regions in pathogen genome for developing new drugs & vaccines.
synthetic biology
- Design and construction of artificial biological pathways
- Redesign of existing biological systems
synthetic biology techniques
genetic engineering
biological systems used in industrial context e.g. immobilised enzymes
synthesis of new genes
- replace faulty ones
synthesis of whole new organism
synthetic biology techniques
genetic engineering
biological systems used in industrial context e.g. immobilised enzymes
synthesis of new genes
- replace faulty ones
synthesis of whole new organism
next-generation sequencing
- uses flow cell (plastic slide) instead of gel or capillaries
- millions of DNA fragments bind to slide & replicated in situ in PCR to form clusters of DNA fragments
- clusters imaged and sequenced at same time = ‘massively parallel sequencing’
- constantly being developed
- very fast and efficient (human genome can be sequenced within days)
The two methods of isolating desired gene in genetics engineering
1) restriction nuclease enzymes
2) reverse transcriptase of mRNA –> cDNA
Why are plasmids used as vectors in genetic engineering?
- small circular DNA
- separate from chromosomal DNA & can replicate independently
DNA ligase
reforms phosphodiester bonds between sugar phosphate groups
Transferring the vector: electroporation and electrofusion
electroporation:
- small electric current applied to bacteria
- makes membrane porous, so plasmids enter
- but must control power otherwise could destroy cell
electrofusion:
- tiny electric currents applied to membranes of 2 diff cells
- fuses cells together, forming hybrid/polypoid cell containing DNA from both.
genetic engineering in plants
- agrobacterium tumefaciens = bacterium that causes tumours in plants
- a. tumefaciens & plant cell w/ desired gene undergo electrofusion:
- cellulase removes cell wall
- electrofusion forms polypoid cell
- plant hormones stimulate growth of new cell wall
- callus formation & production of many cloned, transgenic plants
- plants transferred to soil to develop into fully differentiated adult plants
genetic engineering in animals
- harder to manipulate animal cell membranes
- virus = common vector in animals
DNA libraries
- store a living record of the DNA of another organism.
- Source of DNA fragments for further genetic engineering applications & further study of their functions
ethical concerns of GM pathogens
- could be used in biological warfare
- made more virulent
- made resistant to treatment
- largely prohibited area of research as could be harmful to health & safety of the public
Problems
with somatic cell gene therapy
- somatic cells have limited life cycle
- healthy allele passed on every time cell divides
- BUT these cells are replaced from stem cells, which contain the faulty allele
- Therefore, only temporary solution
- A treated individual can still pass on the faulty allele.
Germ line cell gene therapy
- healthy allele inserted into germ cell (usually eggs) or the embryo immediately after fertilisation as part of IVF treatment
- Individual would be born healthy with normal allele
Germ line cell therapy concerns
- ethical and medical
- potential impact on individual is unknown
- human rights of unborn individual violated
- done without consent & irrevocable process
- concerns of future usage enabling people to choose desirable or cosmetic characteristics of their offspring.
