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29 Cards in this Set
- Front
- Back
what is biotechnology?
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Biotechnology – application of biological systems (microorganisms) to obtain a product (food, antibiotics, vitamins)
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what is Recombinant DNA technology?
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Recombinant DNA technology – procedures by which a fragment of DNA of one organism is incorporated into the genom of a different organism
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What are the goals of genetic engineering?
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Goals of Genetic Engineering
-Eliminate undesirable phenotypic traits in humans, animals, plants, and microbes, (suppression of ripening in tomatoes) -Create organisms that synthesize products humans need (insulin) |
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What are the tools and techniques of Genetic engineering?
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Tools and Techniques of Genetic Engineering
-Restriction enzymes – major tool -Analysis of DNA – gel electrophoresis -Nucleic acid hybridization -DNA sequencing -Polymerase Chain Reaction: PCR |
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What are restriction enzymes?
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Restriction Enzymes
-DNA cutting enzymes -They recognize and cut specific fragments of DNA (sequences of nucleotides in DNA) -They leave single stranded sticky ends of DNA -DNA from different sources cut with the same restriction enzyme will produce the same type of sticky end |
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How do restriction enzymes work?
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-DNA is cut on a specific Palindromic sequence -Palindromes are sequences that are identical when read in opposite directions on two strands
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Describe DNA Gel electrophoresis.
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DNA Gel Electrophoresis
-Separation of DNA fragments based on their size -In agar gel, DNA fragments are subjected to an electrical current -DNA molecule has a negative charge – moves toward the positive pole -Smaller fragments move faster |
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What is acid hybridization?
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Nucleic Acid Hybridization
-A fragment of a single-stranded nucleic acid (DNA, RNA) can hybridize (unite) with another fragment that has a complementary sequence of nucleotides *when discovered, used to measure questions of similarity between two organisms * |
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describe Hybridization with a probe
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Hybridization with a probe
-The method used to detect specific nucleotide sequence in an unknown sample by using a gene probe -Gene probe is a short segment of DNA of a known sequence -A probe carries a radioactive level |
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What is the process in which exact sequence of nucleotides in a DNA segment is determined?
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DNA sequencing
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what is Polymerase chain reaction PCR?
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-Technique by which a small amount of specific DNA fragment can be amplified in vitro
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What is needed for Polymerase chain reaction PCR?
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-PCR machine – thermal cycler
-Target DNA that serves as a template -Supply of 4 nucleotides -DNA polymerase -Primers -Primers are short fragments of DNA that are complementary to the target DNA |
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Describe one PCR cycle.
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One PCR cycle has 3 basic steps:
-Denaturation: 94 degrees Celsius – separation of DNA strands -Priming: 50-65 C primer attached to complementary strand of DNA -Extensions: 72 C DNA polymerase extends the molecule by adding nucleotides -Typically we use 20-40 cycles – millions of copies of DNA |
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How is the process of Recombinant DNA Technology (if you want to clone a gene)?
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Recombinant DNA Technology (if you want to clone a gene)
-A selected gene is removed from the genetic donor -This gene is incorporated into a vector (plasmid or virus) -The vector is inserted into the cloning host (bacteria yeast) |
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What are Vectors?
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-Vectors are DNA molecules into which a segment of foreign DNA can be incorporated
(plasmids, transposons, and viruses) |
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What are the characteristics of Vectors?
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-Vector’s characteristics:
-self-replicating -circular shape -proper size – to be able to accept foreign DNA -must have a promoter -must have a gene for antibacterial resistance |
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How is foreign DNA inserted?
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Inserting foreign DNA into cells
Transformation -Plasmid from the surrounding environment is taken up by a cell -Cells have to be made competent – by soaking them in calcium chloride |
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Describe Screening of bacteria that contain foreign DNA.
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-The vector (plasmid) contains the gene for ampicilin resistance
-Just those cells that have been transformed can grow on medium containing ampicilin |
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What is synthetic DNA?
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-DNA synthesis machine
-Short fragments of DNA (120 molecules) can be synthesized -We must know the sequence of the DNA fragment that we want to synthesize |
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What are the applications of Recombinant DNA technology.
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-Pharmaceutical and Therapeutic Applications
-Protein synthesis -Vaccines, DNA vaccines -Genetic screening -DNA fingerprinting -Gene therapy |
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What is Somatostatin?
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Somatostatin
-Human hormone used for treatment of giantism (an excessive secretion of growth hormone) -Before 500,000 sheep brains were needed to produce 5mg of somatosin -Today – 8 liters culture of generally engineered bacteria to obtain equivalent amount |
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WHat are subunit vaccines?
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-A protein portion of the virus is cloned
-Hepatitis B vaccine (Saccharomyces cerevisaie carries the virus gene on a plasmid) -Advantage – there is no chance of becoming infected during vaccination |
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What are DNA vaccines?
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A single gene from that pathogen is artificially copied and multiplied
-That gene is then injected into a muscle. Muscle cells tend to take up this gene and use it as one of their own genes, making the product -The immune system will recognize that product as foreign, and will start producing antibodies |
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What are the agricultural applications of Recombination DNA?
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Agriculture Applications:
-Transgenic organisms – recombinant plants and animals altered by addition of genes from other organisms -Improving Crops -Herbicide resistance -Salt tolerance -Freeze resistance -Pest resistance -Improvements in nutritional value and yield |
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How are transgenic plants created?
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-Agrobacterium tumefaciens – plant parasite that can incorporate its DNA into plant’s genom by
using Ti plasmid -Ti plasmid can be engineered to contain a new gene |
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What are transgenic animals created?
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Why to create a transgenic animal?
-Many human genes have better expression in animals than in bacteria -The product (protein) can be collected in milk or semen -Foreign genes are inserted into an embryo by using a virus or an injection |
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What is Gene therapy?
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-Mosty preliminary work
-Missing or defective genes replaced with normal copies -Possible treatment for: cystic fibrosis, sickle cell anemia, some types of hemophilia, some types of diabetes |
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what is Antisense DNA and RNA?
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-Antisense strand of DNA recognizes and binds to the complementary mRNA fragment
-This results in blocking the expression (translation) of the harmful gene -Antisense drugs are being researched to treat cancers and other diseases |
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Describe genetic screening.
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-Many genetic diseases can be detected by genetic engineering techniques
-Technique: Southern blotting (Ed Southern 1975) `-Inherited forms of breast cancer |