Virology (20) - Virus Properties And Classification

Front 1

What are the two basic components of a virus?

Back 1

Genome (RNA or DNA) surrounded by a protective coat.

Front 2

Viruses are obligate ____ ____.

Back 2

intracellular parasites

Front 3

In what environment will viruses multiply?

Back 3

Only in living cells.

Front 4

Viruses are dependent on host cell machinery for what two functions?

Back 4

1) protein synthesis
2) stored cellular energy

Front 5

How do viruses make use of host cells?

Back 5

degrade cells and use cellular components

Front 6

Viruses are assembled from what?

Back 6

simple, repeating, self-assembling subunits

Front 7

def - Capsid

Back 7

protein coat

Front 8

def - Virion

Back 8

complete virus particle

Front 9

What is found in the core of a virus?

Back 9

nucleic acid (DNA or RNA), core proteins

Front 10

What is the function of a virus capsid?

Back 10

protect genome

Front 11

Capsids are (symmetrical/asymmetrical).

Back 11

symmetrical (helical, icosahedral or complex)

Front 12

Capsids function in attachment of virus to ____ ____.

Back 12

host cell

Front 13

Capsids are composed of capsomeres, which are ____ ____.

Back 13

protein polypeptides

Front 14

def - Nucleocapsid

Back 14

core + capsid

Front 15

Where are the lipids in a lipid envelope derived?

Back 15

from host cell membranes

Front 16

Glycoproteins embedded in the lipid envelope interact with host cells and the environment. Name two important functions of these glycoproteins.

Back 16

1) responsible for viral attachment
2) target for host immune response (antigens)

Front 17

There may be a protein layer between the capsid and envelope. What makes this layer?

Back 17

matrix or tegument proteins

Front 18

Name three physical characteristics of naked capsids.

Back 18

1) stable
2) resistant to heat, pH, drying, detergents, proteases
3) released by cell lysis

Front 19

Describe three basic transmission characteristics of naked capsids.

Back 19

1) easily spread
2) longer survival time
3) may survive gut

Front 20

Name three physical characteristics of enveloped viruses.

Back 20

1) labile (easily damaged)
2) susceptible to heat, pH, drying, detergents
3) released by budding or cell lysis

Front 21

Describe three basic transmission characteristics of enveloped viruses.

Back 21

1) must remain wet
2) close contact, droplets
3) destroyed in gut

Front 22

Do capsids with helical symmetry have envelopes?

Back 22

no

Front 23

What units make up the structure of a helically symmetrical capsid?

Back 23

RNA helix with associated nucleoproteins

Front 24

Name two examples of viruses with helical symmetry.

Back 24

1) TMV
2) Filoviruses (Ebola, Marburg)

Front 25

What are some characteristics of icosahedral symmetry?

Back 25

repeating subunits (pentamere, capsomere)
self-assembled subunits from a few proteins (5)
encloses largest possible volume
very strong

Front 26

Can complex virus structures be defined by a mathematical equation?

Back 26

nope

Front 27

Name two viruses with complex structure.

Back 27

1) Pox virus
2) T4 Bacteriophage

Front 28

How large are poxviruses?

Back 28

>300 nm

Front 29

Name four virion morphologies.

Back 29

1) icosahedral
2) spherical
3) rodlike
4) bullet
5) filamentous

Front 30

Three families with naked icosahedral morphology.

Back 30

1) Papova-
2) Picorna
3) Adenoviridae

Front 31

Name two families with enveloped icosahedral morphology.

Back 31

1) Herpes-
2) Togaviridae

Front 32

Are there any viruses of human medical importance with naked helical morphology?

Back 32

nope.

plant viruses (TMV, Bacteriophage M13)

Front 33

Name three families with enveloped helical morphology.

Back 33

1) Orthomyxo-
2) Paramyxo-
3) Filoviridae

Front 34

Name three families with complex morphology.

Back 34

1) Poxviridae
2) Bacteriophage T4
3) Lambdavirus

Front 35

How do viral genomes compare to prokaryotes and eukaryotes in size?

Back 35

small!

Front 36

Which virus has the smalles genome?

Back 36

parvovirus (5.5 kbp)

Front 37

Name three viruses with the largest genomes.

Back 37

1) pox virus (195 kbp)
2) cytomegalovirus (239 kbp)
3) mimivirus (>800 kbp)

Front 38

What is the size range for bacterial genomes?

Back 38

900 kbp to 5,000 kbp

Front 39

What is the size range for human chromosomes?

Back 39

50,000 kbp to 245,000 kbp

Front 40

If a virus has an RNA genome, what are the three varieties it may present?

Back 40

1) Single stranded RNA (- or + sense, + = coding)
2) Double stranded RNA
3) Segmented (several pieces of RNA)

Front 41

If a virus has a DNA genome, what are three variations?

Back 41

1) single stranded (only Parvociridae)
2) double stranded (most)
3) linear (most) or circular (Papovaviridae)

Front 42

How is the name of a virus family indicated?

Back 42

-iridae (e.g. Herpesviridae)

Front 43

How is the name of a virus sub-family indicated?

Back 43

-irinae (e.g. alphaherpesvirinae)

Front 44

Viruses are grouped into families based on what four criteria?

Back 44

1) enveloped v. naked virions
2) genetic material (RNA v. DNA, ds v. ss, +ssRNA v. -ssRNA)
3) capsid symmetry
4) size

Front 45

Picorna - genome? enveloped or naked?

Back 45

+RNA, naked

Front 46

Calici - genome? enveloped or naked?

Back 46

+RNA, naked

Front 47

Toga - genome? enveloped or naked?

Back 47

+RNA, enveloped

Front 48

Corona - genome? enveloped or naked?

Back 48

+RNA, enveloped

Front 49

Rhabdo - genome? enveloped or naked?

Back 49

-RNA, enveloped

Front 50

Filo - genome? enveloped or naked

Back 50

-RNA, enveloped

Front 51

Orthomyxo - genome? enveloped or naked?

Back 51

-RNA, enveloped

Front 52

Paramyxo - genome? enveloped or naked?

Back 52

-RNA, enveloped

Front 53

Bunya - genome? enveloped or naked?

Back 53

-RNA, enveloped

Front 54

Arena - genome? enveloped or naked?

Back 54

-RNA, enveloped

Front 55

Reo - genome? enveloped or naked?

Back 55

+/-RNA, double capsid

reo=wierdo

Front 56

Retro - genome? enveloped or naked?

Back 56

+RNA via DNA, enveloped

Front 57

Pox - genome? enveloped or naked?

Back 57

DNA, enveloped

Front 58

Herpes - genome? enveloped or naked?

Back 58

DNA, enveloped

Front 59

Hepadna - genome? enveloped or naked?

Back 59

DNA, enveloped

Front 60

Parvo - genome? enveloped or naked?

Back 60

ssDNA**, naked

Front 61

Polyoma - genome? enveloped or naked?

Back 61

DNA, naked

Front 62

Papilloma - genome? enveloped or naked?

Back 62

DNA, naked

Front 63

Adeno - genome? naked or enveloped?

Back 63

DNA, naked