MIDTERM 10 - Introduction to Viruses Flashcards
100 years ago, researchers couldn’t imagine submicroscopic particles, so they described the infectious agent as __________
Contagium vivum fluidum
__________, an American chemist, isolated tobacco mosaic virus in 1935
Wendell Stanley
Wendell Stanley, an American chemist, isolated __________ in 1935
Tobacco mosaic virus
Wendell Stanley, an American chemist, isolated tobacco mosaic virus in __________
1935
Are acellular obligate intracellular parasites that are 20 to 300 nm thick
Viruses
2 components of the virus structure (NE)
Nucleocapsid, Envelope
A protein-nucleic acid complex representing the packaged form of the viral genome (Components of the viral structure)
Nucleocapsid
Contains the genetic material, either DNA or RNA (Components of nucleocapsid)
Nucleic acid core
Coat that encloses the viral genome (Components of nucleocapsid)
Capsid/Protein coat
Are protein subunits that comprise the capsid
Capsomeres
A lipid-containing membrane that surrounds the nucleocapsid of some viruses (Components of the viral structure)
Envelope
Other name for glycoprotein spikes found in the surface of the virus; used for attachment to target cell receptors
Peplomers
3 types of virus symmetry (IHC)
Icosahedral/Cubic, Helical, Complex
Has 20 faces and 12 vertices; usually appear spherical and can be observed in DNA and RNA viruses (Types of virus symmetry)
Icosahedral/Cubic
Resemble long rods that may be rigid or flexible; can be observed in RNA viruses (Types of virus symmetry)
Helical
Has a complicated structure (Types of virus symmetry)
Complex
Refers to the complete, mature virus particle which contains the nucleocapsid and envelope
Virion
Refers to the single stranded naked RNA that is only 300 to 400 nucleotides long and has no protein coat
Viroid
Refers to a proteinaceous infectious particle that is highly resistant to inactivation by heat, formaldehyde, and UV light that inactivate viruses
Prion
Refers to a single folded viral polypeptide chain
Subunit
Based on virion morphology, genome structure, and strategies of replication (Viral taxonomy)
Family (ends in -viridae)
Based on biological, genomic, physicochemical, or serologic differences (Viral taxonomy)
Genus (ends in -virus)
Share the same genetic information and ecological niche; has descriptive common names (Viral taxonomy)
Species
Family of medium-sized viruses that cause various respiratory infections in humans; some cause tumors in animals (Viruses with double-stranded DNA; nonenveloped)
Adenoviridae
Family of small viruses that cause warts and cervical and anal cancer in humans (Viruses with double-stranded DNA; nonenveloped)
Papovaviridae
Family of very large, complex, brick-shaped viruses that cause smallpox, molluscum contagiosum, and cowpox (Viruses with double-stranded DNA; enveloped)
Poxviridae
Family of medium-sized viruses that cause various human diseases such as fever blisters, chickenpox, shingles and infectious mononucleosis; causes a type of human cancer called Burkitt’s lymphoma (Viruses with double-stranded DNA; enveloped)
Herpesviridae
Family of viruses that causes Fifth disease and anemia in immunocompromised patients (Viruses with single-stranded DNA; nonenveloped)
Parvoviridae
Family of viruses that causes generally mild respiratory infections transmitted by arthropods; Colorado tick fever is the best-known (Viruses with double-stranded RNA; nonenveloped)
Reoviridae
Family of viruses that includes the polio-, coxsackie-, and echoviruses, are the most common cause of colds (Viruses with single-stranded RNA w/ + strand; nonenveloped)
Picornaviridae
Family of viruses that include causes of gastroenteritis and hepatitis E (Viruses with single-stranded RNA w/ + strand; nonenveloped)
Caliciviridae
Family of viruses that include those viruses transmitted by arthropods, diseases include eastern equine encephalitis, western equine encephalitis, and chikungunya (Viruses with single-stranded RNA w/ + strand; enveloped)
Togaviridae
Family of viruses that can replicate in arthropods that transmit them; diseases include yellow fever, dengue, Zika, and West Nile encephalitis (Viruses with single-stranded RNA w/ + strand; enveloped)
Flaviviridae
Family of viruses that are associated with upper respiratory tract infections and the common cold; includes the SARS virus and MERS-CoV (Viruses with single-stranded RNA w/ + strand; enveloped)
Coronaviridae
Family of bullet-shaped viruses with a spiked enveloped; causes rabies and numerous animal diseases (Viruses with single-stranded RNA w/ - strand; has one strand of DNA and is enveloped)
Rhabdoviridae
Family of enveloped, helical viruses; includes Ebola and Marburg (Viruses with single-stranded RNA w/ - strand; has one strand of DNA and is enveloped)
Filoviridae
Family of viruses that cause parainfluenza, mumps, and Newcastle disease in chickens (Viruses with single-stranded RNA w/ - strand; has one strand of DNA and is enveloped)
Paramyxoviridae
Family of viruses that depend on coinfection with hepadnavirus (Viruses with single-stranded RNA w/ - strand; has virusoid or satellite RNA)
Deltaviridae
Family of viruses that have envelope spikes that can agglutinate red blood cells (Viruses with single-stranded RNA w/ - strand; has multiple strands of DNA and is enveloped)
Orthomyxoviridae
Family of viruses that can cause hemorrhagic fevers such as Korean hemorrhagic fever and Hantavirus pulmonary syndrome; commonly associated with rodents (Viruses with single-stranded RNA w/ - strand; has multiple strands of DNA and is enveloped)
Bunyaviridae
Family of viruses that has helical capsids that contain DNA-containing granules; causes lymphocytic choriomeningitis, Venezuelan hemorrhagic fever, and Lassa fever (Viruses with single-stranded RNA w/ - strand; has multiple strands of DNA and is enveloped)
Arenaviridae
Family of viruses that include all RNA tumor viruses; can cause leukemia and tumors in animals (Viruses with single-stranded RNA, produce DNA, and is enveloped)
Retroviridae
Family of viruses that causes hepatitis B and liver tumors (Viruses with double-stranded DNA, use reverse transcriptase, and is enveloped)
Hepadnaviridae
2 cycles involved in the viral multiplication of bacteriophages (LL)
Lytic cycle, Lysogenic cycle
Cycle that ends with the lysis and death of the host cell (Cycles involved in the viral multiplication of bacteriophages)
Lytic cycle
Cycle where the host cell remains alive (Cycles involved in the viral multiplication of bacteriophages)
Lysogenic cycle
Phage attaches to the host cell (Stages of the lytic cycle)
Attachment
Phage penetrates the host cell and injects its DNA (Stages of the lytic cycle)
Penetration
Phage DNA directs synthesis of viral components by the host cell (Stages of the lytic cycle)
Biosynthesis
Viral components are assembled into virions (Stages of the lytic cycle)
Maturation
Host cell lyses, and new virions and released (Stages of the lytic cycle)
Release
Are viruses that can be grown either in suspensions of bacteria in liquid media or in bacterial cultures on solid media
Bacteriophages
Refers to cells grown in culture media in the laboratory
Cell line
2 types of cell line (PC)
Primary, Continuous
Cell line derived from tissue slices; dies out after only a few generations (Types of cell line)
Primary cell line
Cell line derived from human embryos; lasts about 100 generations (Example of primary cell line)
Diploid cell lines
Cell line that are transformed (cancerous); has an indefinite number of generations (immortal cell line) (Types of cell line)
Continuous cell line
Cell line that is isolated from the cancer of Henrietta Lacks (Example of continuous cell line)
HeLa cell line
Effects that involve the deterioration of cell monolayer caused by viruses
Cytopathic effects (CPE)
Serological methods, such as __________, are the most commonly used means of viral identification
Western blotting
Visible signs of viral infections are called __________
Cytopathic effects (CPE)
Effects of viral infections that involve cell death
Cytocidal effects
Effects of viral infections that involve cell damage but not death
Noncytocidal effects
__________ are cytokines that are central to the antiviral innate immune response of the host
Interferons
Refers to the process of virus mediated gene transfer
Transduction
Means capable of giving rise to several different cell types
Pluripotent