Viro Lec - Part 1 Terms Flashcards
complete infective virus particle
Virion
protein shell that encloses the nucleic acid core (DNA/RNA but never both)
Capsid
smallest infectious agents causing disease in plants; viral diseases in plants
Viroids
the capsid together with the enclosed nucleic acid
Nucleocapsid
morphologic units seen on the surfaces of icosahedral virus particles
Capsomeres
outer coat some viruses acquire as they penetrate or are budded from the nuclear or cytoplasmic membrane
Envelope
morphologic units composed of structural units embedded in the envelope
Peplomers
general term to describe situations where mixed infections result in enhanced yields of one or both viruses in the mixture
Complementation
viruses that infect bacterial cells
Bacteriophages
the. mechanism by which a particular base sequence in messenger RNA produces a specific amino acid sequence in a protein
Translation
how specific information encoded in a nucleic acid chain is transferred to messenger RNA
Transcription
required by certain defective closely related viruses to replicate
Helper virus
functionally deficient particles in some aspect of replication and may interfere with the replication of normal viruses
Defective virus
viruses that cannot reproduce from their nucleic acid and virions are non-infectious
Satellite viruses
Members of certain bacterial genera also are unable to replicate outside a host cell
EALR
Ehrlichia, Anaplasma, Legionella, and Rickettsia
RNA reversely turns into DNA
Reverse transcriptase
simples of viruses; virion is composed of viral structural proteins
Parvoviruses (family Parvoviridae)
Virion comprises viral proteins and RNA
Picornaviruses (family Picornaviridae)
Virion more complex with envelope; mature by budding through different host cell membranes that are modifi ed by the insertion of viral proteins
Herpesviridae and Paramyxoviridae
the major type of protein present on the exterior of the membrane of enveloped viruses
Glycoproteins
it is of the same sense as mRNA; directly capable of translation to protein
Positive sense or polarity
Type of RNA virus that the genomic nucleotide sequence is complementary to the of mRNA
Negative sense or polarity
Period of time between the penetration of the virus particle into the host cell and the production of the first new virus particle
Eclipse period
used as a quantitative or relative measure of the pathogenicity of the infecting virus
Virulence
Routes of Virus Entry
● Via respiratory tract
● Via the Gastrointestinal tract
● Via the skin
● Other routes (genital tract, conjunctiva)
protects the respiratory tract; consists of a layer of mucus produced by goblet cells
Mucociliary blanket
Different defenses protecting the gastrointestinal tract
- Acidity of the stomach
- Layer of mucus
- Antimicrobial activity of digestive enzymes
- Bile and pancreatic secretions
- Innate and adaptive immune mechanisms
Enteric infections by certain viruses first infect the:
- Epithelial cells lining the GI mucosa
- Specialized M cells that overlie intestinal lymphoid aggregates (Peyer’s patches)
Examples of viruses that cause purely enteric infection that are acid and bile resistant
rotaviruses and enteroviruses
viruses that are both transmitted by and replicate in arthropod vectors
Arboviruses
introduction of a virus by skin penetration that is a result of veterinary or husbandry procedures
Iatrogenic
Type of viral spread that if a virus enters through the respiratory tract; Viral shedding is limited to respiratory secretions.
Local Spread
When a virus spreads through the bloodstream; Viral shedding occurs from multiple mucosal surfaces
Viremic Spread
have glycoproteins (hemagglutinin) necessary for binding with specifi c receptors that allows their entry to cells
Orthomyxoviruses
abnormal structures that form in the nucleus or cytoplasm of a host cell during a viral infection
Inclusion bodies
spherical inclusions in nerve cells that are a sign of rabies infection
Negri bodies
cytokines made by lymphocytes
Interleukins
key family of cytokines
Interferons
