Microbiology Chapter 9 Flashcards
the use of microorganisms, cells, or cell components to make a product
Naturally occuring organims and their products
Examples: foods, antibiotics, vitamins, enzymes
Biotechnology
Recombinant DNA (rDNA) technology/Genetic engineering
insertion or modification of genes to produce desired proteins
terminology for genes of interest
Vector: self-replicating DNA used to carry the desired gene to a new cell
Clone: population of cells arising from one cell; each carries the new gene
rDNA Technology does
Obtain DNA DNA “manipulation” Put DNA into a form that can be taken up by a cell Put DNA into a cell Select cells with desired DNA Clone
pathways to obtaining DNA
Genomic libraries are made of pieces of an entire genome stored in plasmids or phages
Complementary DNA (cDNA) is made from mRNA by reverse transcriptase
DNA via polymerase chain reaction
Synthetic DNA is made by a DNA synthesis machine
To make multiple copies of a piece of DNA enzymatically Used to: Clone DNA for recombination Amplify DNA to detectable levels Sequence DNA Diagnose genetic disease Detect pathogens Thermus aquaticus
Properties of Polymerase Chain Reaction (PCR)
Cut specific sequences of DNA
Naturally destroy bacteriophage DNA in bacterial cells
Cannot digest (host) DNA with methylated cytosines
Restriction Enzymes
Vector Properties
Purpose: Carry new DNA to desired cell
Need to (self) replicate
Shuttle vectors can exist in several different species
Plasmids and viruses can be used as vectors
Inserting Foreign DNA into Cells
DNA can be inserted into a cell by: Transformation Competence Electroporation Protoplast fusion Gene gun Microinjection
E. coli Used because it is easily grown and its genomics are known Need to eliminate endotoxin from products Cells must be lysed to get product Saccharomyces cerevisiae Used because it is easily grown and its genomics are known May express eukaryotic genes easily Plant cells and whole plants May express eukaryotic genes easily Plants are easily grown Mammalian cells May express eukaryotic genes easily Harder to grow
Product considerations from microbes
Human enzymes and other proteins
Subunit vaccines
Nonpathogenic viruses carrying genes for pathogen’s antigens as DNA vaccines
Gene therapy to replace defective or missing genes
Therapeutic Applications
Understanding DNA Sequencing organisms’ genomes Via shotgun sequencing Examine virulence factors DNA fingerprinting for identification Metagenomics
other applications for dna
Nanotechnology
bacteria can make molecule sized particles
uses of Agrobacterium
Bt toxin Bacillus thuringiensis Herbicide resistance Suppression of genes Antisense DNA Nutrition Human proteins
Safety Issues and Ethics of Using rDNA
Need to avoid accidental release
Genetically modified crops must be safe for consumption and for the environment
Who will have access to an individual’s genetic information?
