manipulating genomes CLASS Flashcards
what is the process for the polymerase chain reaction
solution containing- DNA fragments, primers , DNA polymerase and DNA nucleotides
- the solution is heated to 65C to break the hydrogen bonds and separating the strands
- primers are added and the temp is reduced to 55C so that primers can anneal
- temp is raised to 72C and DNA polymerase binds and extends the primers using free nucleotides
what are restriction enzymes
they are used to obtain DNA fragments from a genome
.some sections have palindromic sequences
.restriction enzymes recognise specific sequences and cut/digest at those sites
.restriction enzymes are complementary to the active site making them specific
what is gel electrophoresis
.it uses a electrical current to separate DNA fragments via size
.agarose gel is used as it has large pores
.nucleotides are negatively charged and so are attracted to the anode
.larger fragments cant move as fast than smaller fragments
.left for a certain amount of time so that not all the fragments reach to the end
gel electrophoresis for proteins
.as they have different charges they are mixed with a chemical to denature them
.this ensure that all the proteins have the same charge
what is the chain terminating method for DNA sequencing
.it enables us to determine nucleotide sequences on DNA fragments
process for the chain termination method
.the sequencing mxiture goes through PCR
.many copies are made (amplified) of the DNA strands
.the strands are then split into single strands by breaking the hydrogen bonds
.and the single strands are used as template strands for new DNA using DNA polymerase and free DNA nucleotide
.terminator bases end the process as they have a specific active site(they are marked with fluorscent marker)
.the new strands are separated via size and terminals identfied
process for genome sequencing
.the DNA fragment is split into smaller fragments as the method can only be used on fragments with less than 1000 base pairs
.restriction enzymes cut the plasmid so that BACs can be incorporated for gene libary
.many copies of the segment are made by bactial culture
.BAC segments are removed and cut into smaller overlapping fragments by restriction enzymes
.the DNA goes through PCR and each fragment is sequenced
.the sequences of each overlapping segements are compared by computers
.the sequence of the whole BAC segment is determined
what is the process for genetic engineering
.DNA containing the disired gene is obtained using a restriction enzyme
.recombiant DNA is made by isolating the vector DNA and cutting it open using the R.E
.by using the same R.E, sticky ends of the vector DNA are complimentary to the DNA fragment
.the DNA fragment is inserted into the vector DNA by using DNA ligase which joins the sugar-phosphate
.vector is used to transfer the recombinant DNA into bacterial cells
.bacteriophage injects DNA into the bacterial cells which integrate with the bacterial DNA
.plasmid vectors are placed in a mixture with the host cells and electric field is created
.this increases the permeability of the host plasma membranes allowing plasmids to enter via electroporation
why and how are soybeans modified
.they are susceptible to insects pests
.
so the GM soybean contains a gene that codes for a protein that is poison to the insects
.the gene is taken from bacillus thuringiensis bacteria and is put into plasmid from agrobacterium tumefaciens
what are the ethical issues for genetic modification of food
pros-
.less use of pesticides
.increased yield and food
cons-
.less biodiversity
.vulnerable to disease
what are the uses for gentically modified pathogen
.they can give potential treatments of disease
.tumor cells have receptors for poliovirus so GM the virus to inactivate the disease causing genes
what are the ethical issues for genetically modifing pathogens
pros-
.can treat previously untreatable diseases
cons-
.lab troubles and mass outbreak of pathogen
.the GM might unGM itself
.someone with ill intensions can cause serious damage
what are the uses for genetically modified animals
.pharming
.antithrombin deficiency = more blood clots
.GM goat embryo and insert it into female = offspring produce milk with antithrombin
.selective breed disired offspring
what are the ethical issues for animal genetic modification
pros-
.drugs can be made in large quantites
cons-
.can have harmful side effects to the animal
.using animals as our assets
what are the ehtical issues for the ownership of GM organisms
pros-
.money for the developer which encourages competition and innovation
cons-
.poorer countries may not be able to afford the products
what is gene therapy
altering alleles inside cells to cure genetic disorders
what is somatic gene therapy
.altering somatic cells
.used for cystic fibrosis which is a recessive disease that damages the respiratory system
.a functioning dominant allele is inserted into the epithelial cells lining the lungs
.but offspring would not inherit the new gene as sex cells haven’t been altered
what is germline gene therapy
.altering sex cells e.g. zygote and early embryonic stem cells
.results in all the cells in the organsim containing the altered DNA and so can be passed on to the offspring
.illegal to be done in humans
what are the ethical issues for gene therapy
pros-
.prolong lives of people who suffering life threathing disorders
.improves quality of life by easing symptoms
.can decrease overall num of people suffering from genetic orders and cancer
cons-
.technology can be used for other things
.expensive
.potential for the therapy to cause more harm
what are the disadvantahes of gene therapy
.inserted alleles can be overexpressed and so result in other problems
.vectors can be recognised as foreign
.allel could be inserted into the wrong place with in the DNA
.effects could be short term for somatic therapy
