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43 Cards in this Set
- Front
- Back
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Biotechnology
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use of scientific and engineering principles to alter or manipulate organisms,cells or biomolecules to achieve specific practical, commercial, or medical goals(aka applied biology)
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Early (Classical) Biotechnology
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-began 10,000+ years ago
Ex. -Fermentation by yeast, bacteria (beer, wine, cheese) -selective breeding of plants(wheat) -selective breeding of animals(dogs, sheep, horse) -discovery of penicillin(accidental) -using viruses(smallpox) to make vaccines |
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Genetic Engineering
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Molecular (Modern) Biotechnology
-modification of an organism's genetic material (add, delete, changing a gene) |
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What are the goals of genetic engineering?
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-to learn about cellular proceses(hereditary)
-to treat genetic disorders (CF, SCID, hemophilia, sickle cell) -to achieve efficient production of biomolecules(insulin) -to make better plants and animal for agriculture |
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Recombinant DNA
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DNA that has been altered by combining genes from diff. organisms sometimes from diff. species-can be made in viruses, yeast, bacteria-then insert into plant of animal
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transgenic organisms
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animals or plants that contain and express DNA from another species
aka genetically modified organisms (GMO) |
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Bacterial Transformation
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DNA from one bacterium becomes incorporated into another bacterium
-incorporated DNA usually released fro dead bac. cell -DNa may be from another species -DNA may be in form of fragments(from dead cells) -DNA ma be in form of plasmid |
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plasmid
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small rind of DNA with 1000->100,000 nucleotides
-may be released after death or it may be passed from bacterium to bacterium during conjugation(sexual reproduction in bacteria) |
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What are the benefits of bacterial transformation?
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-allows antibiotic-resistant bacteria to survive, grow, pass on resistance
-allows bacteria to spread easily to another host-versatility |
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Viral Transduction (Infection)
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viruses transfew their genetic material into cells during infection
-viral genes replicate-redirect protein synthesis -most viruses infect only similar species: bacteriophages->bacteria; plant viruses->plant species; animal viruses sometimes infect unrelated species (ex. rabies & influenza) |
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What is cross spread infection?
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Rabies-humans, dogs, bats, racoons, squirrels
Influenza-bird, humans, pigs |
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Gene transfer
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host's genes may be incorporated into viral genome or viral genes may be incorporated into host's chromosomes
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Genome
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total complement of genetic info for organism
HGP=Human Genome Project Francis Collins-NIH(Fed. gov't) Craig Ventor-Celera Genomics |
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Proteome
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Catalog of all human proteins and their interactions:
Where is the protein? What does it do? When does it do it? Which gene? *doing this to devise drugs with fewer reactions |
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Applications of Biotechnology in Forensics
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-pertaining to legal proceedings
-identification of victims, criminals (evidence) -analysis of skin, blood, saliva, semen -uses polymerase chain reaction, short tandem repeats and gel electrophoresis |
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Polymerase Chain Reaction
(PCR) |
-production of number of copies of specific pieces of DNA
-Developed by Kary Mullis in 1986 (Nobel Prize in 1993) -PCR requires a primer -2 primers are needed, one to mark each end of the DNA strand to be copied -Put in test tube: 2 primers + free nucleotides (A,T,C,G) + special DNA polymerase + original DNA *special DNA comes from bacteria in Hot Springs |
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primer
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small piece of complementary DNA or RNA that serve as a starting point for DNA polymerase to start replicating the DNA
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Steps of Polymerase Chain Reaction
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1. Heat tube to 90-95 C- to break hydrogen bonds -> makes DNA a single-strand
2. Lower temp. to 50 C- primers bing to DNA 3. Raise temp to 70-72 C-Free nucleotides bind to single strands of DNA 4. Repeat steps 1 through 3 |
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Short Tandem Repeats (STR)
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-small repeating segments of DNA (2 to 5 nucleotides long, usually found in introns)
-used to identify individuals most humans have between 5 & 15 copies of the STR -in forensics, a match of 10 STRs means that there is less than 1 in a trillion chance that DNA is from 2 different people |
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Gel Electrophoesis
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-technique used to separate DNA fragments by size, forming distince bands on gel
-DNA is placed in wells on gel slab in buffer solution -electrical current applied causes negatively charged DNA to move to positive electrode -smaller fragments move faster (through holes in gel) -fragments are made visible by probes -allows for side by side comparision -produces DNA fingerprints |
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probes
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single strand of complementary DNA marked by either dye or radioactivity
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fingerprints
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a pattern of short tandem repeats from a DNA sample
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Biotechnology in Agriculture
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-most GMOs are plants (corn, rice, soy beans, cotton, oats)
-contain genes from other species (transgenic) -most plants have been modified to resist insects, resist herbicides, or for better flavor & ripening (accomplished by adding or inhibiting bacterial enzymes) |
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Bt gene
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from Bacillus thuringiensis
-causes damage to digestive of insects *if larvae of Monarch butterfly ingests, kills them |
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Steps to produce a transgenic plant
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1. obtain desired gene-isolate gene from an organism or synthesize gene in lab
2. insert gene into plasmid - use restriction enzyme-isolated from bacteria - enzyme cuts double-stranded DNA at specific nucleotide sequence -if same restriction enzyme is used to cut bacterial plasmid DNA, & the DNA of desired gene then they are complementary "sticky ends" -DNA ligase will bind Bt dene into plasmid 3. Bt plasmid gets inserted into plant |
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Edible vaccines
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for diarrhea, Hep B
- first used potatoes, but that failed so they used bananas |
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"Plantibodies"
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possible production of human antibodies in genetically engineered plants
ex. antibodies for genital herpes (experiment) -fast source of antibodies |
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GMO animals
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-animals are more difficult to modify
-usually, transgenic animals are formed by injecting desired DNA into fertilized egg (using a virus as a vector (carrier of gene) -egg divides, implanted in surrogate mother -offspring may express trait: GH(fish,pigs), extra milk(cows), milk protein(in sheep-CF protein found) |
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Concerns about GMO animals
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Animals may develop ulcers, arthritis, sterility. If animals released into the wild the genes could be passed on.
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Restriction Fragment Length Polymorphisms
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-Restriction enzymes have cut DNA into fragments of various lengths, and the homologous chromosomes may differ in length
-RFLPs can be separated and visualized using gel electrophoresis -RFLP analysis can be used to diagnose sickle-cell anemia |
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DNA Probes/Arrays
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-probs are single strands of DNA marked by dye or radioactivity
-used in arrays-fliter paper with probes bound onto it -Person's DNA is cut up, labeled, and washed over the array in solution -DNA strands will only bind to the right spots -Used to diagnose CF(many alleles code for CF protein) |
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Therapeutic proteins
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made by inserting gene into bacterial plasmid
ex. Interteron-treats Hepatitisis & Arthritis Humalin-human insulin GH-growth hormone Activase-enzyme, tissue plasminogen activator, helps w/ heart attack (After) Leukine-cytokine (immune system) clotting factors-Factor VIII |
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Treatment for CF
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-insert "normal" gene(for protein for normal CL- pumps)
-infect cells with viruc, normal gene gets inserted into cells of lungs so that cells will now have the right DNA and will produce functioning Cl- pumps (can be iven as a nasal spray) |
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Treatment for SCID
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-defective immune cells-usually due to single, recessive genetic defect
-WBCs remvoed, infected with functioning gene, cultured, returned to blood. (Process needs to be repeated because WBCs don't have a long life span) -X-linked SCID(defective cytokine receptors -also treated w/ gene therapy -bone marrow cells are removed, normal gene inserted into bone marrow stem cells, then returned to bone marrow -may provide a more permanent treatement -risk of developing leukemia |
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GMOs
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-may contain genes that never existed before
-contain genes from diff. species -have advantages(resist insects, herbicides, provide larger harvest, provide nutrients) ex. golden rice-contains Beta carotene (precursor to Vitamin A) could prevent blindness -problems w/ Golden rice-not enough beta carotene, rice only grows in certain locations, expensive, low fat diets prevent proper absorption |
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Possible toxicity
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-Bt is not toxic to mammals, but may be harmful to harmless insects
-fish and cattle contain GH-okay-unless organism is in wild -Genetically cows = BGH (more milk)-humans already make GH |
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Possible Allergens
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-to foreign proteins
-GMsoy beans have gene from Brazil Nuts |
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1st Transgenic plant & 1st transgenic goat
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-Flav'r Sav'r tomato
...tasted bad -"Number One", made at Tufts ...purpose was to make insulin from her milk |
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Environmental concerns
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wind carries pollen (w/ genes for GMOs)-harder to control
-could "superweeds" be formed? ...oat, barley, wheat, similar to wild type |
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amniocentesis
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fetal cells removed from amniotic fluid for analysis
What is done with info? |
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chronic villus sampling
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fetal cells remvoed from villi of chorion for analysis
What to do with info? |
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Creation of Embryos
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for use as tissue donors
-better chanec of MHC match for family member (sibling) -many embryos created, screened, nonmatching=discarded |
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Alteration of Human Genome
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may be possible to alter genes in fertilized egg to:
-fix disorders like CF, SCID -alter physical appearance -improve athletic ability, intelligence |
