Intro. to Virology Flashcards
Only eradicated animal virus
Rinderpest
zoonosis
infectious diseases transmitted from animals to humans
virology
the study of viruses and viral diseases
virologist
someone who studies viruses
viruses - living or non living
non living
virus
nucleic acid genome surrounded by a protein coat and in some cases, other layers of material, such as a lipid envelope. They do no possess standard cellular organelles. They cannot make proteins by themselves. All are obligate intracellular organisms.
viron
a complete virus particle that consists of an RNA or DNA core with a protein coat sometimes with external envelopes and is the extracellular infective form of a virus
viroid
an infectious particle smaller than any of the known viruses, an agent of certain plant diseases. Consists only of an extremely small circular RNA molecule, lacks protein coat
Edward Jenner
inoculated some “cowpox matter” repeatedly into healthy boy who became immune. First vaccine!
Louis Pasteur
injected dried, potassium hydroxide treated, infected rabbit brain into boys bitten by rabid dogs, both recovered.
Charles Chamberland
invented a filter that has pores smaller than bacteria (viruses fit through)
Martinus Beljerinck
used the chamberland filter to filter virus, filtered material caused disease, material remaining in filter did not cause disease.
Friedrich Loeffler and Paul Frosch
passed the first animal virus through chamberland filter—- foot and mouth disease
Dr. Walter Reed
discovered that yellow fever was spread via mosquito
Peyton Rous
isolated first tumor-causing animal virus
Woodruff, Goodpasture, and Burnet
reported propagating fowlpox virus in embryonated hen’s eggs
smallest virus
porcine circovirus type 1 (17nm)
parvoviruses (18-22nm)
largest virus
pandoravirus (400nm)- plants
poxvirus (200nm)- animals
pleomorphism
ability of some viruses to alter their shape or size
what virus class has a double layered capsid
Reotoviruses
helical symmetry
capsomeres and nucleic acids are wound together to form a helical or spiral tube
naked helical virus
just the helical capsid
enveloped helical virus
enclosed helix in an envelope
cubic/icosahedral symmetry: what are the components
solid with 12 corners (verces, fixed number), 20 facets (equilateral triangle faces, this number can change), and 30 edges
triangulation number and equation
relation between the number of pentagons and hexagons of the icosahedron
T=h^2 + h * k + k^2
complex symmetry
virions are composed of several parts, each with separate shapes and symmetries, such as Poxviruses and Bacterial viruses (bacteriophage) also contain icosahedral heads and helical tails
enveloped viruses
viruses surrounded by a lipid bilayer with embedded proteins. these are less stable in the environment
two types of viral proteins found within the envelope
glycoproteins
matrix protein
external glycoproteins
anchored in the envelope, major antigens of the virus and involved in hemagglutination, receptor binding, antigenicity, and membrane fusion
channel proteins
hydrophobic proteins that form a protein lined channel through the envelope. alters permeability of the membrane
matrix protein
link the internal nucleocapsid to the lipid membrane envelope, role in virus assembly, recognition site of nucleocapsid at the plasma membrane
positive sense RNA virus
infectious genome: 5’–>3’, similar to mRNA
negative sense RNA virus
noninfectious genome: 3’–>5’, complementary to mRNA
antigenic drift
minor changes, virus may become resistant to antiviral drugs, change in antigenicity
antigenic shift
huge changes, whole viral genome can change
recombination
two viruses infect the same cell, they are mixed together taking one part of one and another of the other. Non-segmented genome
reassortment
important for high genetic diversity in viruses with segmented genomes. Two viruses become very mixed together.
lysins
hydrolytic enzymes produced by bacteriophages to cleave the host cell wall
retroviral interase (IN)
enzyme produced by a retrovirus (such as HIV) that enables its genetic material to be integrated into the DNA of the infected cell
reverse transcriptase (RT)
enzyme used to generate complementary DNA (cDNA) from a RNA template
nucleic acid polymerases
viral genome replication
neuraminidases
enzymes that cleave glycoside bonds and allow release of viruses from the host cell
incomplete virion
virion without nucleic acid (empty capsid)
defective virion
a virus that cannot replicate because it lacks a full copy of viral genes. Can replicate with help
DIP (defective interfering particles)
when the defective viruses can not replicate, but can interfere with other congeneric mature virion entering the cells
pseudovirion
contains non-viral genome within the viral capsid. Host nucleic acid.
pseudotypes
when related viruses infect the same cell, the genome of one virus may be enclosed in heterologulus capsid of the second virus
