Ch 10 Flashcards
What is recombinant DNA?
DNA in which one or more segments or genes have been inserted, either naturally or by laboratory manipulation, from a different molecule or from another part of the same molecule, resulting in a new genetic combination
What is biotechnology?
The use of living organisms or other biological systems in the manufacture of drugs or other products or for environmental management, as in waste recycling: includes the use of bio reactors in manufacturing, microorganisms to degrade oil slicks or organic waste, genetically engineered bacteria to produce human hormones, and monoclonal antibodies to identify antigens
What is genetic engineering?
The development and application of scientific methods, procedures, and technologies that permit direct manipulation of genetic material in order to alter the hereditary traits of a cell, organism, or population
What are gene probes?
A short stretch of DNA of a known sequence that will base-pair with a stretch of DNA with a complementary stretch of DNA if it exists in a sample
What is the process of gel electrophoresis?
- Samples of DNA are placed in compartments in a soft agar gel and subjected to an electrical current
- The negative charge on the phosphate groups cause the DNA to move toward the positive pole on the gel
- The rate of movement of DNA through the gel is based on the size of the fragments
What is the function of gel electrophoresis?
- useful in characterizing DNA fragments
- allow for comparison of genetic similarities among samples in a genetic fingerprint
What are palindromes?
A segment of double-stranded DNA in which the nucleotide sequence of one strand reads in reverse order to that of the complementary strand.
Know the function of restriction endonucleases
- clip DNA crosswise at selected positions
- recognize foreign DNA
- capable of breaking the phosphodiester bonds between adjacent nucleotides on both strands of DNA
- protect bacteria and archaea from bacteriophage or plasmids
What is the advantage of bacteria producing restriction endonucleases?
Restriction enzymes are the bacteria’s form of an ‘immune system’ against viruses (which can infect bacteria).
When viruses try to insert their own DNA into a bacteria’s genome, the restriction enzymes detect this foreign DNA and cut it out so that the viruses can’t replicate and kill the cell.
What is the function of reverse transcriptase?
- replicate HIV and other retroviruses
- able to convert RNA into DNA
What is the function of reverse ligase?
- necessary to seal sticky ends together by rejoining the phosphate-sugar bonds cut by endonucleases
- main application is final splicing of genes into plasmids and chromosomes
Know the process and function of PCR (include primers, enzymes used, and temps).
- utilizes a thermal cycler that automatically performs the cyclic temperature changes
- three basic steps:
- Denaturation
- Priming
- Extension
- DNA polymerase used
Given two DS fragments of DNA, determine how many would be present after 5 PCR cycles.
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What is transformation?
transformation is the genetic alteration of a cell resulting from the direct incorporation of exogenous genetic material from its surroundings through the cell membran
How is the size of a strand of DNA usually given?
The relative sizes of Nucleic acids are denoted by the number of base pairs (bp) they contain
Example: an average gene in E. coli is 1,300 bp or 1.3 kilo bases
What is a genetic library?
- genes maintained in a cloning host and vector, just like microbial pure culture
- collections of cDNA clones that represent the entire genome of numerous organisms
What are FISH probes used to identify?
- observed microscopically for the presence and location of specific genetic marker sequences on genes
- a very effective way to identify genes on chromosomes
- also effective in identifying bacteria living in natural habitats without culturing them
- used to detect RNA in cells and tissues
What are features in a cloning host?
- rapid turnover; fast growth rate
- can be grown in large quantities using ordinary culture methods
- no pathogenic
- genome that is well delineated (mapped)
- capable of accepting plasmid or bacteriophage vectors
- maintains foreign genes through multiple generations
- will secrete a high yield of proteins from expressed foreign genes
Know the steps in recombinant DNA (gene cloning and product retrieval).
- select gene of interest
- Excise gene with restriction endonuclease
- isolate gene with gel electrophoresis
- insert gene into vector (plasmid or virus) with complementary bases
- transform host cell with vector
- replicate gene when cell reproduces
- produces protein. transcribe and translate (can make gallons of the protein)
What are examples of genetically engineered proteins?
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What example of genetically engineered proteins was first approved for human use?
Insulin
What are characteristics of a transgenic animal?
- production of biofuels
- unlike yeast and bacteria, animals can express human genes in organs and organ systems that are very similar to those of humans
What is gene therapy?
Repair or correction of a faulty gene in humans suffering from a fatal or debilitating disease
What is antisense therapy?
In antisense gene therapy, short single-stranded pieces of chemically modified nucleotides, known as oligonucleotides are inserted into cells. These short strands are sometimes abbreviated as “oligos” and are chemically engineered to be complementary to specific mRNA in the cell
