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57 Cards in this Set
- Front
- Back
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What are the three main ways bacteria pass information from cell to cell?
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1) transformation
2) transduction 3) conjugation |
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point mutation
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aka substitution
-is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide |
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insertion mutation
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- add one or more extra nucleotides into the DNA.
They are usually caused by transposable elements, or errors during replication of repeating elements (e.g. AT repeats). If caused by a transposable element, they can be reversed by removal of said element. |
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base substitution mutation
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mutation that occurs when one or more nucleotides are exchanged for different nucleotides.
-When only one nucleotide is changed a base substitution mutation is referred to as a point mutation |
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frameshift mutation -
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- is a genetic mutation caused inserts or deletes a number of nucleotides that is not evenly divisible by three from a DNA sequence.
It will most likely not be functional. |
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A _________ mutation causes the reading of codons to be different, so all codons after the mutation (with a few exceptions due to redundancy) will code for different amino acids.
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frameshift
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deletion mutation
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- remove one or more nucleotides from the DNA.
- Like insertions, these mutations can alter the reading frame of the gene. They are irreversible. |
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spontaneous mutation
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- a mutation that occurs in the natural environment.
These events occur randomly and are observed infrequently. |
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How do plasmids function for bacteria?
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A plasmid is a DNA molecule separate from the chromosomal DNA and capable of autonomous replication
(means it can make more of itself, uses the enzymes of the cell in which they are found). |
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Plasmids are the form of circular DNA that is primarily transferred by _________
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conjugation
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What is the purpose of gel electrophoresis?
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Gel electrophoresis is used to separate DNA molecules based upon their size.
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In most cases the electrophoresis gel is a _______ _______ whose composition and porosity is chosen based on the weight and composition of the target of the analysis
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crosslinked polymer
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What causes DNA to move in gel electrophoresis?
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Uses the electromotive force (EMF) that is used to push or pull the DNA through the gel matrix.
By placing the molecules in wells in the gel and applying an electric current, the molecules will move through the matrix at different rates. |
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DNA is _________ charged, so the fragments will migrate toward the __________ charged electrode.
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negatively, positively
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What is the purpose of PCR?
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-to amplify (make many copies of) a specific region of DNA
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How do restriction enzymes work?
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- Makes two incisions, one through each of the sugar-phosphate backbones (i.e., each strand) of the double helix without damaging the nitrogenous bases.
- Each enzyme recognizes a specific 4-6 base pair palindrome, and will cut the DNA at or near that sequence on both strands of the DNA molecule. |
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What is a restriction enzyme?
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aka restriction endonuclease
- an enzyme that cuts double-stranded DNA. |
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What are examples of medical products made through biotechnology processes?
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Bacteria can be genetically engineered to express pharmaceutical proteins or other products usually only produced by animal cells such as:
- human growth hormone - human insulin - gamma inteferon - vaccines - etc -Review table 9.2 for more examples. |
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Name 4 characteristics used to classify bacteria.
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- Size
- shape - Gram stain - special stains - biochemical tests - colonial morphology (colony color, size and shape when grown on a nutrient agar plate) - nucleotide sequence homologies (16s rRNA sequences) |
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Name a group / genus of bacteria described by the following:
catalase + bacteria |
in general all obligate aerobes are catalase positive.
In lab, was use to differentiate between staphs (catalase +) and streps (catalase -) |
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Name a group / genus of bacteria described by the following:
bacteria that are very hard to kill (2 groups) |
- the endospore Gram positive rods, Bacillus and Clostridium
- enterics - members of the family Enterobacteriaceae, Gram negative rods that reside in the intestinal tract of humans or in rich soil. Enterics that are part of the normal flora of the intestine include Enterobacter, Klebsiella, and Proteus species, as well as most strains of E. coli. |
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Name a group / genus of bacteria described by the following:
bacteria that move by means other than flagella |
spirochetes, move by means of an axial filament.
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Name a group / genus of bacteria described by the following:
bacteria that are hard to stain (3 groups) |
Mycobacterium, Nocardia, Mycoplasma
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Name a group / genus of bacteria described by the following:
bacteria associated with water (2 groups) |
Legionella and Vibrio species are associated with aquatic environments
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Name a group / genus of bacteria described by the following:
normal skin bacteria |
staph species such as S. aureus and S. epidermidis
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Give a genus of bacteria described as:
humans obtain it from reptiles |
Salmonella
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Give a genus of bacteria described as:
carried by ticks (more than one name applies) |
Rickettsia rickettsii - Rocky Mountain Spotted Fever
Borrelia burgdorferi - Lyme disease |
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Give a genus of bacteria described as:
coagulase + bacteria (more than one name can apply) |
Staph aureus
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Give a genus of bacteria described as:
causes pneumonia (more than one name applies) |
-Klebseilla
-Legionella -Chlamydia -Streptococcus -Mycoplasma |
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Give a genus of bacteria described as:
is anaerobic |
- Bacteroides spp.
- Clostridium spp. - the lactic acid bacteria |
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What are the main structural components of a virus?
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- the capsid (protein coat)
- the genetic info (either RNA or DNA) |
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Give three characteristics used to classify viruses.
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1) Genome structure- DNA or RNA, single stranded or double stranded, a single molecule or segmented
2) Virus particle structure- isometric (icosahedral) helical (rod-shaped) or pleomorphic (irregular in shape) 3) presence or absence of a viral envelope |
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What are the main steps of viral replication?
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1) Attachment/Adsorption
2) Penetration and Uncoating 3) Biosynthesis 4) Maturation 5) Release |
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What is the difference between a virulent phage and a temperate phage?
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- Virulent phage undergo a productive infection that results in lysis of the cell.
- Temperate phage undergo lysogenic replication that results in the integration of their DNA into the host chromosome or their replication as a plasmid and the passing on of the phage genetic material to daughter cells upon cell division. (leads to host cell lysis) |
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What is a latent infection?
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persistent infection in which a symptomless period is followed by reactivation of the virus with accompanying symptoms. Infectious virus particles cannot be detected until the disease is reactivated.
- The symptoms of the initial and reactivated forms of the disease may differ. |
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Name 2 ways that bacteriophage replication is different from animal virus replication.
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1) whole virus penetrates animal cells, genome only for bacteriophage, i.e. with phage, the protein coat is left outside the cell.
2) penetration and uncoating are seperate steps for animal viruses, are the same step for bacteriophage. |
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Name three ways viruses are cultured in the lab.
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1) inside living animals
2) embryonated chicken eggs 3) cell or tissue culture |
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How are viruses identified in cell culture?
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- by their CPE or cytopathic effects, a characteristic change of the tissue culture cell's appearance that is often specific for a particular virus.
- One of the most common CPE's is an inclusion body. |
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Name three DNA viruses
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Herpes, Papillomavirus, Adenovirus
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Name three RNA viruses
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Picornavirus, Reovirus, Rhabdovirus
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What is the importance of knowing which viruses are RNA viruses?
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RNA viruses are more mutagenic than DNA viruses
- For example in the case of retroviruses such as HIV, the reverse transcriptase enzyme that converts the viral RNA into DNA that integrates into the infected host cell’s chromosome has no proofreading ability. Therefore, errors (i.e. putting the wrong bases in the sequence) are not corrected and leads to the production of slightly different viral proteins which may no longer be recognized by the host immune system. |
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Define: obligate intracellular parasite
Give an example |
must be inside cells to be metabolically active
viruses |
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coliform
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bacteria that ferments lactose
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naked virus
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capsid and genetic material (phages)
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prion
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infectious proteins, usu fatal
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viroid
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infectious RNA, plant pathogens
circular, single stranded RNA |
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examples of prions
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Creutzfeldt-Jacob
Mad Cow-BSE Scrapie Kuru Chronic Wasting Disease |
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Examples of DNA Viruses
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Adenovirus (child diarrhea)
Pox Virus (Smallpox) Papillomavirus (warts/HPV) |
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more ex of DNA viruses
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Hep B
Herpes (simplex 1 and 2) Epstein Barr-Mono Varicella Zostter- Chickenpox cytomegalovirus (CMV) |
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RNA viruses
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Picornavirus includes..
-Poliovirus (polio) -Rhinovirus (colds) -Hep A |
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RNA Viruses
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Coronavirus (colds)
Influenza (A&B, flu) RSV (resp. Synctitial virus) |
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RNA Viruses
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Togavirus (Rubella, MMR, Hep C)
Paramyxovirus (mumps, measles, MMR) Rhabdoviruses (rabies) Reovirus-Rotavirus Retrovirus-HIV |
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inclusion body
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spots in cell where you can find virus particles
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Two Types of Viral replication
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1) Lytic (Virulent)
2) Lysogenic (Temperate) |
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2 Types of Viral Release
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1) Lysis (cell death)
2) budding (pooping) |
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Electroporation
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form of artificial competence; electric current puts holes in bacteria so that DNA can enter
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Define semiconservative replication
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1 strand of each parent strand goes into each daughter cell
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