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Chapter 14
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76
Microbiology
Undergraduate 1
11/17/2010

Additional Microbiology Flashcards

 


 

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Term
Tobacco Mosaic Virus
Definition
Dimitri Ivanowsky and Martinus Beiherinck studied what virus?
Term
Foot and Mouth Disease and Yellow Fever
Definition
Walter Reed studied?
Term
Bacteriophages
Definition
Frederick Twort and Felix d'Herelle studied what?
Term
viruses
Definition
in 1930's it was discovered nonliving agents composed of nucleic acid and protein, which are called?
Term
a culture technique using chicken eggs
Definition
Alice M Woodruff and Ernest W. Goodpasture developed what?
Term
Viruses
Definition
tiny infectious agents, small, obligate intracellular parasites, that lack the machinery for generating energy and large molecules, so they need a host cell to replicate, and genome contains either DNA or RNA
Term
Capsid
Definition
the protein coat, made up capsomeres
Term
Nucleocapsid
Definition
made up of the capsid with its enclosed genome
Term
spikes
Definition
help the virus attach to and penetrate the host cell
Term
naked viruses
Definition
composed only of a nucleocapsid
Term
enveloped viruses
Definition
viruses surrounded by an envelope
Term
Virion
Definition
a completely assembled, infectious virus outside its host cell
Term
Helical Viruses
Definition
Helical Symmetry
Term
Icosahedral Viruses
Definition
Icosahedral Symmetry
Term
Complex Symmetry
Definition
Viruses that have both helical and icosahedral symmetry
Term
host range
Definition
what organisms the virus can infect, depending on the capsid structure
Term
tissue tropism
Definition
viruses infect certain cell or tissue types within the host
Term
specific receptor
Definition
the virus needs this in order to invade the host cell
Term
Viruses
Definition
nomenclature and classification do not use conventional taxonomic groups
Term
a classification system
Definition
The International Committee on Taxonomy of Viruses (ICTV) is developing this
Term
DNA Viruses
Definition
contain single- or double- stranded DNA genomes
Term
RNA Viruses
Definition
contain single- or double-stranded RNA genomes
Term
+ Strand RNA Viruses
Definition
this virus has mRNA genomes
Term
- Strand RNA Viruses
Definition
these viruses have RNA strands that would be complementary to mRNA
Term
Retroviruses
Definition
replicate indirectly through a DNA intermediate using an reverse transcriptase enzyme
Term
T-even group bacteriophages
Definition
Virulent Viruses that carry out a lytic cycle of infectionin prokaryotes
Term
phage nucleic acid
Definition
contains only a few of the genes needed for viral synthesis and replication
Term
1. Attachment: Viral Replication
Definition
occurs when a phage's tail fibers match with a receptor site on the bacterium's cell wall
Term
2. Penetration: Viral Replication
Definition
occurs when the phage tail releases lysozme to dissolve a portion of the cell wall. Phage DNA is injected into the bacterial cytoplasm
Term
3. Biosynthesis: Viral Replication
Definition
the production of new phage genomes and capsid parts
Term
4. Maturation: Viral Replication
Definition
the assembly of viral parts into complete virus particles
Term
5. Release Viral Reproduction
Definition
the exit of virions from the bacterium, it is also called the lysis stage when the cell is ruptured
Term
Temperate Phages
Definition
do not lyse the host, they insert their DNA into the bacterial chromosome as a prophage (lysogenic cycle)
Term
1. Attachment Animal Viral Replication
Definition
host plasma membrane via spikes on the capsid or envelope
Term
2. Penetration Animal Viral Replication
Definition
Since receptor sites vary from person to person, some people are more susceptible to a certain virus than others
Term
Animal Viruses
Definition
usually taken into the cytoplasm as intact nucleocapsids
Term
uncoating
Definition
the separation of the capsid from the genome
Term
5. Release Animal Viral Replication
Definition
After the new viruses are assembled, envelop proteins are incorporated into a cellular membrane, the virus buds, taking the membrane part with it as an enzyme
Term
Provirus
Definition
Some DNA viruses and retroviruses insert their genome into the host chromosome
Term
Reverse Transcriptase
Definition
Retroviruses use this to transcribe their RNA to DNA
Term
provirus
Definition
encodes a repressor protein that prevents activation of the viral genes necessary for replication
Term
Latent proviruses
Definition
immune to the host body's defeneses, they are propagated each time the cell's chromosome is reproduced
Term
River's Postulates
Definition
filtrates of infectious materials shown not to contain bacterial or other cultivatable organisms must produce the disease or its counterpart, filtrates must produce specific antibodies
Term
Cytology
Definition
uses light microscopy to examine cells for cytopathic effects (CPEs) of viral infection
Term
Cultivation and Detection of Viruses
Definition
Most often uses cells in culture
Term
primary cell culture
Definition
cells form a monolayer in a culture dish
Term
monolayer
Definition
the type of cell culture depends on the virus to be cultivated
Term
plaques
Definition
Viruses can be detected by the formation of these, a clear zone within the monolayer
Term
Viruses
Definition
can be grown in fertilized eggs
Term
cancer
Definition
an uncontrolled growth and spread of cells
Term
Tumor
Definition
clone of abonormal cells
Term
Benign Tumor
Definition
Normally, the body surrounds a tumor with a capsules of connective tissue
Term
Malignant Tumor
Definition
Tumor cells can break free from the capsule and spread to other tissues of the body (metastasis)
Term
Viruses
Definition
responsible for up to 20% of human tumors
Term
carcinogens
Definition
60-90% of human cancers are associated with these
Term
oncogenic viruses
Definition
transform infected cells by these
Term
Epistein Barr virus
Definition
linked to Burkitt Lymphoma, a tumor of the jaw
Term
Human Papilloma Virus (HPV)
Definition
associated with cervical cancer
Term
Oncogene Theory
Definition
suggests that protooncogenes normally reside in the chromosomal DNA of a cell
Term
Oncogenes
Definition
these can be transformed by radiation, chemical carcinogens, DNA damage, viruses
Term
Virus
Definition
infects its DNA as a provirus into a cell's chromosome next to a protooncogene
Term
Virus Replication
Definition
when triggered, the provirus replicates its DNA as well as few adjacent host genes
Term
V-Oncogenes
Definition
protooncogenes captured in the viral genome, when the oncogenic viruses infect another cell, this is under the virus's control, not the cell's control, they can code for growth factors, stimulating uncontrolled cell proliferation
Term
Emerging Viruses
Definition
usually arise through natural phenomena, may spread to new populatiosn or may expand host range
Term
Genetic Recombination
Definition
may lead to "new" viruses
Term
Mutation
Definition
occasionally be advantageous and create a new virus or stain a virus
Term
Regressive Evolution Hypothesis
Definition
Viruses degenerate life-forms
Term
Cellular Origins Hypothesis
Definition
Viruses are derived from subcellular components and macromolecules that escaped from cell walls and replicated inside hosts
Term
Independent Entities Hypothesis
Definition
Viruses coevolved with cellular organisms from a self-replicating moelcule present on primitive Earth
Term
Viroids
Definition
infectious RNA particles, tiny fragments of RNA that cause diseases in crop plants, replication cycle and disease causation process for these are not understood, one hypothesis suggests introns
Term
Prion
Definition
infectious proteins
Term
Transmissible Spongiform Ecephalopathies (TSEs)
Definition
can occur in humans and other animals, (e.g. mad cow disease), are neurologic degenerative diseases that can be transmitted within or between species
Term
Protein Only Hypothesis
Definition
predicts that prions are composed only of protein and contain no nucleic acids
Term
Abnormal Prions
Definition
Has a different shape than normal prions, causes TSEs, may spread TSEs when infectious prions bind to normal prions, causing normal prions to change shape and become one of them, do not trigger an immune response
Term
Death of Host
Definition
occurs from nerve cell death leading to sponge-like holes in brain tissue. Symptoms include, dementia, weakened muscles, and loss of balance , resulting from insoluble aggregates of abnormal prions in the brain
Term
Variant CJD (Creutzfeldt-Jakob Disease)
Definition
the human form of TSE is this
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