Chapter 19: genetic technology Flashcards
define recombinant DNA
DNA made from joining pieces from 2 or more different sources
give an overview of genetic engineering
- ) required gene is obtained
- ) gene is placed into vector
- ) gene is inserted into recieving organism’s cell
what is the role of restriction enzymes?
- cut through DNA at specific points
- catalyses the hydrolysis reaction that breaks the sugar-phosphate backbone to form sticky ends
what is the role of DNA ligase?
- forms recombinant DNA
- catalyses the condensation reaction that joins the sugar-phosphate backbones of the plasmid and DNA
define ‘transgenic bacteria’
bacteria that contains DNA that has been added to its cells following genetic engineering
outline the steps of PCR
- ) double stranded DNA sample is chosen
- ) heated to 95 degrees, strands are separated
- ) primers added, reduced to 55 degrees, primers anneal
- ) temp raised to 72 degrees. DNA polymerase binds and extends primers using free nucleotides
what is electrophoresis?
the process that separates DNA fragments based on size. It is used for identification and analyasis of DNA
outline the steps of electrophoresis
- ) DNA fragmented by restriction enzymes
- ) DNA placed into wells. Gel put into buffer solution and an electric current passed through
- ) DNA is stained
what are DNA probes?
single-stranded DNA that is complementary to the DNA being investigated. It can be labelled with markers
outline the steps involved in a microarray
- ) test and reference single-stranded DNA identified
- ) DNA labelled with fluorescent dyes
- ) microarray with DNA probes
why are promoters important for genetic engineering?
inserted alongside the gene so that RNA polymerase can bind to begin transcription
what is the function of reverse transcriptase?
- mRNA is isolated
- reverse transcriptase makes the complementary DNA strand
- DNA ligase makes the c.DNA (complementary strand)
define ‘gene therapy’
treating genetic disorders with genetic engineering
give 3 disadvantages of somatic gene therapy
- ) treatment is short-lived: the gene will not divide to pass on the allele
- ) difficulty getting allele into genome. Genetically modified virus vectors mean the host becomes immune, and liposomes are also ineffective
- ) genetic manipulations are restricted to the actual patient
give an overview of SCID
- caused by the presence of defective gene for making adenosine deaminase enzyme
- a retrovirus was engineered to contain the normal ADA gene
- viral infection means ADA gene is taken up
symptoms of SCID
- defective ADA causes the destruction of T-lymphocytes
what is cystic fibrosis?
- caused by recessive allele of gene making CFTR
- CFTR acts as a chlorine ion transporter
- less H20 moves out of cell, so mucus is thicker
disadvantages of genetic modification
- no long-lasting effects
- risk of immune response to transferred gene
- viruses may cause immune responses
- disorders caused by multiple alleles cannot be treated
advantages of genetic modification
- can eliminate/ prevent hereditary conditions
- people born with conditions have a chance at life
- can eradicate diseases for future generations
bioinformatics definition
the collection, processing and analyasis of biological information and data using computer software
genetic screening definition
analysing someone’s DNA to check for the presence of a particular allele
what are sticky ends?
unpaired bases
give examples of vectors
plasmids, viruses and liposomes
