Virus structure and taxonomy -- L1

Question 1

Small, obligate, intracellular parasites

Answer 1

VIRUS

Question 2

In their simplest form, viruses consist of what 2 things?

Answer 2

• nucleic acid

- protein

Question 3

There are no _____ viruses

Answer 3

free living

Question 4

Viruses can either be ____ or ____? but never both

Answer 4

DNA or RNA

Question 5

Because viruses can be DNA or RNA they can be ____ or ____ stranded

Answer 5

single or double

Question 6

usually viruses are haploid or diploid?

Answer 6

haploid meaning they only have one copy of the gene

Question 7

What is a nucleocapsid composed of?

Answer 7

1) capsid – protein coat

2) viral nucleic acid

Question 8

complete virus particle is called?

Answer 8

virion

Question 9

What are some components of the structure of a virus?

Answer 9

nucleocapsid
± lipid envelope (host derived)
± matrix protein between nucleocapsid
envelope (‘packing material’)

Question 10

What two types of proteins are seen in viruses?

Answer 10

1) structural

2) non-structural (enzymes)

Question 11

Used to construct components of the virus

Answer 11

structural proteins

Question 12

provides protection of viral nucleic acid

Answer 12

structural proteins

Question 13

important in host immune response

Answer 13

structural protein

Question 14

viral envelope derived from cell membranes?

Answer 14

lipids

Question 15

most often as peplomers (spikes) extending outwards from the envelope

Answer 15

glycoproteins

Question 16

used in nucleic acid and protein metabolism

Answer 16

non-structural (enzymes) proteins

Question 17

causes shutdown of host cell function

Answer 17

non-structural (enzymes) proteins

Question 18

What are the 2 types of capsid symmetry?

Answer 18

1) Icosahedral (cubic)

2) helical

Question 19

virions self-assemble from where?

Answer 19

protein subunits

Question 20

What are the 4 components of helical capsids?

Answer 20

1) peplomer
2) lipid envelope
3) matrix protein
4) helical nucleocapsid

Question 21

a lipid bilayer formed when a virus particle buds through cellular membranes

Answer 21

envelope

Question 22

Host derived virus envelopes have what specific component?

Answer 22

peplomers (spikes)

Question 23

Enveloped virions are often _____ as the envelope is not rigid

Answer 23

pleomorphic

Question 24

In formal virus taxonomy, the names of orders, families, subfamilies, genera and species are always printed in _____ and the first letters of
the names are _____.

Answer 24

italics;capitalized

Question 25

What is an emerging infectious disease?

Answer 25

An existing disease that is rapidly increasing in incidence or geographic range.

Question 26

What is the size range of viruses?

Answer 26

~17-300 nm
RBC diameter = 7000 nm
Bacteria = 1000 nm

Question 27

Can viruses be seen on a light microscope?

Answer 27

No- its resolution is only ~300nm. Viruses are smaller than that. Need to use an electron microscope.

Question 28

What are prions and viroids in relation to viruses?

Answer 28

Infectious agents simpler than viruses.
Viroids- infectious RNA
Prions- infectious proteins

Question 29

-virales refers to the classification of _____.

Answer 29

Order

Question 30

The word ending for the classification of family is…

Answer 30

-viridae

Question 31

-virinae refers to the classification of ___.

Answer 31

Sub-family

Question 32

T/F The ending of the Genus name is virus.

Answer 32

True. E.g. Lyssavirus