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Chapter 9 Partial
Genetic Engineering Outline
78
Microbiology
Undergraduate 1
11/16/2010

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Term
Genetic Engineering
Definition
The use of bacterial and microbial genetics to isolate, manipulate, recombine, and express genes
Term
Genetically Modified Organisms (GMOs)
Definition
An organism produced by genetic engineering
Term
Genomics
Definition
The study of an organism’s gene structure and gene function in viruses and organisms
Term
Genetic Recombination
Definition
The process of bring together different segments of DNA; A natural mechanism for DNA transfer from one microorganism to another
Term
Vertical Gene Transfer (VGT)
Definition
the passing of genes from one cell generation to the next; When a mutation occurs in the parent cell, all future generations derived by binary fission from the parent cell will have the same mutation
Term
Horizontal Gene Transfer (HGT)
Definition
The movement of genes from one organism to another within the same generation; a type of genetic recombination that involves the lateral intercellular transfer of DNA from a donor cell to a recipient cell
Term
Horizontal Gene Transfer (HGT)
Definition
If the recipient cell receives from the donor a chromosomal DNA fragment, a plasmid, a transposon, or a combination of all of them containing a gene for antibiotic resistance, the new DNA pairs with a complementary region of recipient DNA and replaces it. This is an example of?
Term
1.) transformation 2.) conjugation 3.) transduction
Definition
Three Distinctive Mechanisms that mediate HGT b/w bacterial cells
Term
1.) Readied for transfer
2.) Transferred to the recipient cell
3.) Taken up successfully by the recipient cell
4.) Incorporated in a stable state in the recipient
Definition
Four Steps of HGT mediation mechanisms
Term
Transformation
Definition
the transfer and integration of DNA fragment from a dead and lysed donor cells to a recipient cell’s chromosome
Term
Transformation
Definition
the conversion of a normal cell into a malignant cell due to the action of a carcinogen or virus; the uptake of a free DNA fragment from the surrounding environment and the expression of the genetic information in the recipient cell, by integration of the DNA fragment, the recipient (transformant) has gained some ability it previously lacked
Term
Transformation
Definition
S. pneumoniae species that causes pneumonia has 2 different strains: a wild-type encapsulated strain, S, because it grows in smooth colonies, and an unencapsulated mutant strain designed R because it s rough and harmless. This is an example of?
Term
Competence
Definition
referring to the ability of a cell to take up naked DNA from the environment; usually incorporates only one or at most a few DNA fragments
Term
Transformation
Definition
in natural environments this process occurs, when bacterial cells die and lyse, the chromosome typically breaks apart into fragments of DNA composed of about 10-20 genes. Uptake of DNA fragments (or a plasmid) by recipient cells appears to occur only at the cell poles, as this is where the competence factors are found and actual DNA uptake has been observed.
Term
Internalization of DNA
Definition
an ATP dependent process and requires DNA binding proteins, cell wall degradation proteins, and cell membrane transport proteins
Term
Gram Positive Internalization of DNA
Definition
Bacillus subtilis and S. pneumoniae degrade one single stranded strand of DNA fragment as it is being taken into the cell, and will replace a similar chromosome sequence. This is example of
Term
Gram Negative Internalization of DNA
Definition
H. influenzae a double stranded DNA fragment is transported into the periplasmic space, but then one strand is digested by a nuclease before transport into the bacterial cytoplasm. This is example of what?
Term
Transformation
Definition
an organism’s ability to cause disease is increased either by acquiring genes from another more lethal organism or two mildly pathogenic organisms cumulate and the recipient becomes more dangerous or have drug resistance by acquiring R plasmids. This is a result of what?
Term
Conjugation
Definition
In Bacteria and Archaea, a unidirectional transfer of genetic material from a live donor cell into a live recipient cell during a period of cell contact; two live bacterial cells come together and the donor cell directly transfers DNA to the recipient cell
Term
Conjugation Pilus
Definition
A protein filament essential for conjugation b/w donor and recipient bacterial cells
Term
The donor cell F+ (because it contains the F Factor) and it contacts the recipient cell F- (because it lacks the F Factor)
Definition
For cell to cell contact, what cell produces the conjugation pilus? Why?
Term
F Factor
Definition
A plasmid containing genes for plasmid replication and conjugation pilus formation
Term
Rolling-Circle Mechanism
Definition
A type of DNA replication in which a strand of DNA “rolls off” the loop and serves as a template for the synthesis of complementary strand of DNA; takes about 5 minutes
Term
Origin of Transfer (OriT)
Definition
The fixed point on an F plasmid (factor) where one strand is nicked and transferred to a recipient cell
Term
Horizontal Gene Transfer
Definition
DNA synthesis in the donor cell produces a new complementary strand to replace the transferred strand, once the DNA transfer is complete, two cells separate
Term
Horizontal Gene Transfer
Definition
In the recipient cell, the new single stranded DNA serves as a template for synthesis of a complementary polynucleotide strand, which ten circularizes to reform an F factor, which completes the F- to F+ conversion and is now capable of conjugating with another F- recipient (only acquires genes on the F factor)
Term
Horizontal Gene Transfer
Definition
It is a highly efficient form of DNA transfer, that spreads rapidly, converting a whole population into plasmid containing cells, and it is the major mechanism for antibiotic resistance transfer
Term
High Frequency of Recombination (Hfr)
Definition
referring to a bacterial cell containing an F factor incorporated into the bacterial chromosome
Term
Hfr strains
Definition
the F factor has attached to the chromosome, this attachment is a rare event requiring an insertion sequence to recognize the F factor
Term
High Frequency of Recombination (Hfr) Conjugation that Transfers Chromosomal DNA
Definition
Once incorporated into the chromosomal DNA, the F Factor no longer controls its own replication, but the Hfr cells trigger conjugation just like an F+ cell. When a recipient cell is present, a conjugation pilus forms and attaches to the F- cell. Then the two cells are brought together. One strand of the donor chromosome is nicked at oriT and a portion of the single-stranded chromosomal/plasmid DNA then passes into the recipient cell
Term
OriT site
Definition
What is the site called in the chromosome in the middle of the F Plasmid gene?
Term
The first genes to enter are only a part of the F factor and they do not make it an F+ donor cell, but the last genes are, and they rarely enter the recipient cell. Conjugation is interrupted by movements that break the bridge b/w cells before complete transfer is finished
Definition
The OriT site in the chromosome is in the middle of the F plasmid gene, so in the recipient cell, How do genes enter the cell? Why do these recipient cells never become F+ donors? how is conjugation is usually interrupted?
Term
Recombinant F- cell
Definition
that received a few chromosomal genes and partial F factor genes from a donor cell during conjugation
Term
The F factor usually detaches from the chromosome, and the enzymes synthesize a strand of complementary DNA. The F Factor forms a loop to assume an existence as a plasmid to make the recipient an F+ donor cell
Definition
If the entire chromosome is transferred to the recipient, what happens to the F factor? How does the recipient become an F+ donor cell?
Term
F' Plasmid
Definition
An F plasmid carrying a bacterial chromosome fragment
Term
F' plasmid
the recipient cell is partially a diploid organisms because they have 2 genes for a gene function
Definition
When it is transferred in subsequent conjugation, the recipient recieves the chromosomal genes excised from donor and the genes from the plasmid DNA, which means it has 2 pairs of genes for the same process. What does this happen to? What does this make the recipient cell?
Term
It occurs in an Hfr cell
an integrated F plasmid
Definition
In this cell, ____breaks free from the chromosome and in the process takes along a fragment of chromosomal DNA. Name the cell this occurs to and what the ___ is.
Term
Gram Negative
Definition
Conjugation occurs b/w cells of various bacterial genera; e.g.like Escherichia and Shigella, Salmonella and Serratia, Escherichia and Salmonella. What are these cells? Gram Negative or Positive?
Term
yes, but they do not use conjugation pili
Definition
Are gram positive microbes capable of conjugation? if so, does it involve conjugation pili?
Term
Gram Positive Conjugation
Definition
it only involves plasmids carrying genes for antibiotic resistance and there are no pili, but the recipient cell secretes substances encouraging the donor cell to produce clumping factors composed of proteins, which causes the factors to come together (clump) the donor and recipient cells, and pores form between the cells to permit the plasmid transfer
Term
Transduction
Definition
The transfer of a few bacterial genes from a donor cell to a recipient cell via a bacterial virus
Term
Bacteriophage/phage
Definition
A virus that infects an replicates within bacterial cells
Term
Lytic Cycle
Definition
A process by which a bacterial virus replicates within a host cell and ultimately destroys the host cell; the phage DNA penetrates the cell, destroys the host chromosome, replicates itself within the cell, and then destroys (lyses) the cells as new phages are released
Term
Virulent Phages
Definition
referring to a virus of microorganism that can be extremely damaging to a host; they are released during the lytic cycle
Term
Lysogenic Cycle
Definition
The events of a bacterial virus infection that result in the integration of its DNA into the bacterial chromosome; the phage DNA integrates into the host chromosome as a prophage and the phages participating are temperate phages. The host cell survives, and as it undergoes DNA replication and binary fission, the prophage is copied and vertically transferred to daughter cells
Term
Lysogenic Cycle
Definition
The events of a bacterial virus infection that result in the integration of its DNA into the bacterial chromosome; the phage DNA integrates into the host chromosome as a prophage and the phages participating are temperate phages. The host cell survives, and as it undergoes DNA replication and binary fission, the prophage is copied and vertically transferred to daughter cells
Term
Prophage
Definition
the viral DNA of a bacterial virus that is inserted into the bacterial DNA and is passed on from one generation to the next during binary fission
Term
Temperate Phages
Definition
referring to a bacterial virus that enters a bacterial cell and then the viral DNA integrates into the bacterial cell’s chromosome
Term
Generalized Transduction
Definition
A process by which a bacteriophage carries a bacterial chromosome fragment from one cell to another
Term
Generalized Transduction
Definition
A process by which a bacteriophage carries a bacterial chromosome fragment from one cell to another
Term
the host cell's chromosome is digested into small fragments. When the new phage DNA is produced, the DNA normally is packaged into new phage particles
Definition
After having DNA injected into the cell, what happens in the host cell?
Term
defective cells
Definition
On rare occasions, a random (general) fragment of host cell DNA may accidently be captured in the packaging process and end up in a phage head rather than the phage DNA. They are fully formed and can infect another cell, they are called ___ b/c they carry no phage genes and cannot replicate themselves after infection.
Term
defective cells
Definition
Following release from the lysed host, ____ attaches to a new (recipient) cell and injects the donor chromosomal DNA into the host cell. Once in the recipient, new genes can pair with a section of the recipient’s DNA and replace the section in a fashion similar to conjugation, the recipient has now been transduced using genes from a donor cell
Term
Specialized Transduction
Definition
the transfer of a few bacterial genes by a bacterial virus that carries the genes to another bacterial cell; as a result of lysogenic cycle, results in transfer of specific genes
Term
Specialized Transduction
Definition
diphtheria bacillus toxin Corynebacterium diphtheriae, staphyloccoal enterotoxins in food poisoning, clostridial toxins in some forms of botulism, and streptococcal toxins in scarlet fever, harbor proviral DNA providing genetic code for the toxins. What are these examples of?
Term
Biotechnology
Definition
the commercial application of genetic engineering using living organisms
Term
Recombinant DNA molecule
Definition
A DNA molecule containing DNA from two different sources
Term
Restriction endonuclease
Definition
A type of enzyme that splits open a DNA molecule at a specific restricted point, important in genetic engineering techniques; recognizes and cuts specific short stretches of nucleotides, leaving mortise like staggered ends
Term
Sticky Ends
Definition
These staggered ends dangling bits of single-stranded DNA extending out from the double-stranded DNA easily attached to complementary ends protruding from another fragment of DNA
Term
Palindrome
Definition
A series of letters reading the same left to right and right to left
Term
DNA Ligase
Definition
An enzyme that binds together DNA fragments; seals the recombinant DNA segments, but normally functions during the DNA replication and repair to seal together DNA fragments
Term
Clones
Definition
A population of genetically identical cells (or plasmids)
Term
Results from Genetic Engineering
Commercial and Practical Applications
Definition
Diabetes a group of diseases resulting from abnormally high blood glucose levels. One is caused by the inability of the body to produce sufficient levels of insulin to control the blood glucose level. Hummulin was the first synthetic human insulin. What is this a result of and an example of?
Term
Bioremediation
Definition
The use of microorganisms to degrade toxic wastes and other synthetic products of industrial pollution, like waste materials or oil pills in attempt to return the environment back to its original condition
Term
Genetic Engineering
Medicine
Definition
microorganisms used to produce a larger quantity of antibiotics and/or produce modified antibiotics to which infectious microbes have yet to show resistance. This results from? and is an example of?
Term
Interferon
Definition
An antiviral protein produced by body cells on exposure to viruses and which trigger the synthesis of antiviral proteins; a set of three naturally produced antiviral agents produced by the human body, two of which block viral replication
Term
Vaccines
Definition
_____ are safer as a result of genetic engineering because they can now contain a part of the whole microbial agent, or isolating a gene that will stimulate the immune system to generate protective immunity. This means that a patient is not exposed to the active virus or bacterium that can cause disease
Term
Genes for herbicide resistance
Definition
These for this have been transplanted from cloned bacterial cells into tobacco plants, demonstrating that these transgenic plants better tolerate the herbicides used for weed control
Term
Transgenic
Definition
referring to an organism containing a stable gene from another organism
Term
Genes spliced
Definition
from a pathogenic virus into tomato plant cells and demonstrated that the cells would produce viral proteins at their surface. The viral proteins blocked viral infection, providing resistance for the transgenic tomato plants
Term
Resistance to insect attack
Definition
This has been introduced into plants using a plasmid carrying a bacterial gene that is toxic to beetle and fly larvae
Term
practical and commercial application of genetic engineering in agriculture
Definition
Food can be changed so that it tastes better, grows faster, and larger, or has a longer shelf life
Term
Argobacterium tumefaciens
Definition
In many experiments, DNA often used in a plasmid, which causes a plant tumor called crown gall, which develops when DNA from the bacterial cells inserts itself into the plant cell’s chromosomes, so by removing the tumor inducing (Ti) gene from the plasmid and then splice the desired gene into the plasmid and allow the bacterial cells to infect the plant; this system works with dicots, like tomatos, potato, soybeans, and cotton. What type of microbe is used in these experiments?
Term
DNA Probes
Definition
A short segment of single stranded DNA used to locate a complementary strand among many other DNA strands; single stranded DNA molecules that recognize and bind to a distinctive and unique nucleotide sequence of a pathogen
Term
Polymerase Chain Reaction (PCR)
Definition
A technique used to replicate a fragment of DNA many times
Term
Polymerase Chain Reaction (PCR)
Definition
The DNA probe binds (hybridizes) to its complementary nucleotide sequence from the pathogen, like velcro straps stick together. To make a probe, scientists first identify the segment or gene in the pathogen that will be the target of the probe. Using this segment, they construct the single-stranded DNA probe
Term
DNA Probes
Definition
What are used for HIV, HPV, and E.coli detection?
Term
DNA microarray
Definition
A series of DNA segments used to study changes in gene expression
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