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Flashcards in RNA Viruses Deck (371)
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1

what is the smallest RNA virus

picornavirus

2

What is the structure of picornavirus

Naked, + icosahedral ssRNA

3

Where does picornavirus replicate?

cytoplasm

4

what is the picornavirus capsid made of?

60 copies of NON-GLYCOSYLATED proteins

5

how does picornavirus enter the cell?

receptor-mediated endocytosis

6

What does a + genome mean?

the genome acts as mRNA

7

What does a - genome mean?

the genome is complementary to the mRNA that will eventually be made

8

What are picornaviruses released from the cell?

cell lysis

9

What does poliovirus use as a receptor?

PVR/CD155

10

What do most other picornaviruses use as a receptor?

ICAM-1

11

What part of the picornavirus capsid binds to the receptor?

canyon region

12

What else can bind to the picornavirus canyon regions?

Antibodies to neutralize virus

13

What is unique about the protein made by picornavirus?

It is translated as 1 protein, and cleaved by a VIRAL PROTEASE

14

What are (-) copies made by picornaviruses?

complementary template used to make more copies of the viral genome

15

What is found at the 5' end of picornavirus RNA?

VPg

16

What is cleaved terminally in picornavirus replication? what is made?

VP0 --> VP2 and 4 mature particles

17

What is VPg?

virally encoded protein that acts as a 5' cap; guides translation and packaging of proteins

18

How is picornavirus transmitted?

Fecal-oral
Respiratory droplets

19

What is unique about rhinoviruses?

They are LABILE at acidic pH; like the upper airway

20

What is unique about the other enteroviruses?

STABLE at acidic pH, like the GI tract

21

What are the examples of the picornavirus family?

Poliovirus
Enterovirus
Rhinovirus
Coxsackie A and B
Hepatitis A

22

What is the most common cause of the common cold ?

Rhinovirus

23

Where do enteroviruses replicate?

mucosa and lymphoid tissue of tonsils and pharynx

M cells and lymphocytes of Peyer's patches

Enterocytes of intestinal mucosa

24

What causes the spread of virus to secondary tissues?

Primary viremia

25

What determines the degree of paralysis in paralytic polio?

the type of neurons affected and degree of damage

26

Who is more severely affected by paralytic polio?

the young and elderly

27

What are the effects of spinal cord involvement in paralytic polio?

paralysis of limbs or complete flaccid paralysis

28

What is affected in bulbar paralysis?

cranial nerves and the respiratory center in the medulla

29

Where is replication of poliovirus restricted to?

GI tract

30

What are the symptoms of poliovirus?

Could be asymptomatic

Could range from mild fever w/ diarrhea to FLACCID PARALYSIS