Virus Classification

Question 1

Obligate intracellular organism

Answer 1

– requires a host cell to replicate

Question 2

Icosahedral

Answer 2

-capsomers make up a multi-sided shape

Question 3

Helical

Answer 3

– capsomers make up a coiled ribbon

Question 4

Complex

Answer 4

– small poxvirus

Question 5

Naked

Answer 5

– more environmentally stable (temp, acid, enzymes), survive in gut, spread by hands, fomites, droplets

Question 6

Enveloped

Answer 6

– more environmentally unstable, must stay wet, spread via large droplets, organ transplants, blood products

Question 7

Envelope

Answer 7

– lipid bilayer acquired by budding through membranes of host cells, contain viral glycoproteins (spikes)

Question 8

Glycoproteins

Answer 8

– contained in lipid envelope, involved in viral attachment to cellular receptors → GP 120 of HIV

Question 9

Non-structural proteins

Answer 9

– derived from viral genome but not incorporated into the viron structure, target of therapy (NS3 of HCV)

Question 10

Receptor-mediated fusion

Answer 10

– virus binds to cell receptor → cell membrane and viral membrane fuse → nucleocapsid is released

Question 11

Receptor-mediated endocytosis

Answer 11

– entire virus is endocytosed into a vesicle → release of nucleocapsid

Question 12

Uncoating at the cell surface

Answer 12

– bind to cell receptor → viral genome only is threaded through membrane pore

Question 13

RNA

Answer 13

– RNA transcriptase to replicate in the cytoplasm, except orthomyxoviruses use part of the nucleus

Question 14

DNA

Answer 14

– DNA-directed RNA polymerase to replicate in the nucleus, except the poxviruses (has its own RNA polymerase)

Question 15

Retrovirus

Answer 15

– both cytoplasm and nucleus using reverse transcriptase, to integrate into the host genome

Question 16

Assembly/Maturation

Answer 16

– can occur in different compartments of the cell

Question 17

Enveloped

Answer 17

– bud through nuclear membrane, ER, or cellular membrane to acquire envelope

Question 18

Classification of viruses:

Answer 18

Order (virales) → family (viridae) → subfamily (virinae) → genus (virus) → species

Question 19

DNA Viruses: HHAPPPy

Answer 19

Hepadna
Herpes
Adeno
Parvo
Papova
Pox

Question 20

Parvo

Answer 20

–smallest, ssDNA, B19

Diseases – Fifth disease, aplastic crisis, spontaneous abortions, hydrops fetalis

Question 21

Adeno

Answer 21

– linear dsDNA

Diseases – acute respiratory, pharyngitis, gastroenteritis, conjunctivitis

Question 22

Papova

Answer 22

– papilloma, polyoma, vacuolating, circular dsDNA

Ex: JC and BK viruses, SV-40

Question 23

Naked: PAP smear, all icosahedral, nuclear replication

Answer 23

Parvo, Adeno, Papova

Question 24

DNA Viruses

Enveloped:

Answer 24

-icosahedral and nuclear, pox = complex, cytoplasm

Question 25

DNA Viruses | Naked: PAP smear, all icosahedral, nuclear replication

Answer 25

Parvo Adeno Papova

Question 26

DNA Viruses | Enveloped: icosahedral and nuclear, pox = complex, cytoplasm

Answer 26

Hepadna Herpes Pox

Question 27

RNA Viruses: | Negative Strand:

Answer 27

Negative Strand: carry RNA polymerase to convert into + strand RNA → proteins

Question 28

RNA Viruses: | Mneumonic – Bunnies myxed with rhabies are thought to fight in delta arenas

Answer 28

``` Bunya Paramyxo Orthomyxo Rhabdo Filo dsRNA Reoviruses Arena ```

Question 29

RNA Viruses: Naked – cytoplasm replication

Answer 29

Filo | Reoviruses

Question 30

RNA Viruses | Enveloped – helical RNA, cytoplasm

Answer 30

``` Rhabdo Paramyxo Orthomyxo Arena Bunya ```

Question 31

Ambisense genome

Answer 31

– viral RNA and complementary RNA code for protein, ex: Bunya and Arena

Question 32

Filo

Answer 32

– filamentous, ssRNA, Ebola and Marburg viruses

Question 33

Reoviruses

Answer 33

– respiratory enteric orphan virus - double capsid, dsRNA, Rotaviruses

Question 34

Rhabdo

Answer 34

– bullet-shaped, Rabies virus

Question 35

Paramyxo

Answer 35

– pleomorphic, ssRNA, cause fusion of cells (syncytia), RSV, measles, mumps, parainfluenza

Question 36

Orthomyxo

Answer 36

– 8 ssRNA with each w/ its own nucleocapsid, cytoplasm and nucleus, influenza viruses

Question 37

Arena

Answer 37

– 2 ssRNA, host ribosomes, rodent vectors

Question 38

Bunya

Answer 38

– 3 ssRNA, insect vectors

Question 39

Positive Strand RNA:

Answer 39

acts like mRNA, polyprotein cleaved into smaller pieces, + strands copied from - strand

Question 40

RNA Positive Strand: | Mneumonic: A retro toga party with flavorful pico de gallo and coronas

Answer 40

``` Retro Toga Flavi Picorna Corona ```

Question 41

RNA Positive Strand: Naked - icosahedral

Answer 41

Calici | Picorna

Question 42

RNA Positive Strand Enveloped

Answer 42

Flavi Toga Corona Retro

Question 43

Flavi

Answer 43

– icosahedral, ssRNA, ARBOvirus (arthropod vector), ex: yellow, fever, West Nile, Dengue, HCV

Question 44

Toga

Answer 44

– icosahedral, ssRNA, ex: Arbovirus, alphaviruses

Question 45

Corona

Answer 45

– ssRNA, largest RNA genome, ex: URTI, common cold

Question 46

Retro

Answer 46

– 2 ssRNA, reverse transcriptase, integrate DNA into host genome, nucleus and cytoplasm replication, oncornavirus (HTLV-1) and Lenitiviruses (HIV)

Question 47

Calici

Answer 47

–ssRNA, Norwalk virus

Question 48

Picorna

Answer 48

– small, ssRNA, Entero (Polio, Coxsackie, Echo, Hep A) and Rhinoviruses (common cold)