viruses and prions

Question 1

in what way are viruses metabolically inert?

Answer 1

they do not posses ribosomes

Question 2

what is the name for a complete virus particle?

Answer 2

virion

Question 3

what does a viral envelope consist of?

Answer 3

lipid membrane

Question 4

do all viruses contain an envelope?

Answer 4

no

Question 5

what is a viral capsid?

Answer 5

protein shell protecting nucleic acid

Question 6

what are the protein units that make up a capsid called?

Answer 6

capsomer

Question 7

what is the viral genome?

Answer 7

RNA or DNA

Question 8

how may viruses be transmitted?

Answer 8

inhalation via respiratory tract, ingestion via GIT, inoculation, congenitally, sexually

Question 9

give an example of a virus transmitted via inhalation

Answer 9

influenza

Question 10

give an example of a virus transmitted via ingestion

Answer 10

Hep A

Question 11

give an example of a virus transmitted via inoculation

Answer 11

Hep B

Question 12

give an example of a virus transmitted congenitally

Answer 12

Herpes

Question 13

give an example of a virus transmitted sexually

Answer 13

HIV

Question 14

give an example of a virus affecting the nervous system

Answer 14

rabies

Question 15

give an example of a virus affecting the respiratory tract

Answer 15

influenza

Question 16

give an example of a virus affecting skin or mucous membranes

Answer 16

herpes

Question 17

give an example of a virus affecting the eyes

Answer 17

ocular herpes

Question 18

give an example of a virus affecting the liver

Answer 18

hepatitis

Question 19

give an example of a virus affecting salivary glands

Answer 19

HIV-SGD

Question 20

give an example of a virus affecting the GIT

Answer 20

norovirus

Question 21

what effects may a virus have on the host cell?

Answer 21

cytopathic effect - cell death
transformation - to cancerous cell
latent infection - no effect on cell function

Question 22

name the steps of viral replication

Answer 22

attachment, penetration, uncaring, synthesis of viral components, assembly, release

Question 23

what occurs during the attachment phase of viral replication?

Answer 23

Virus attaches to host cell membrane and injects DNA/RNA into host - initiating infection

Question 24

what occurs during the penetration phase of viral replication?

Answer 24

cell membrane enfolds around virus, enclosing it into a vacuole. protecting the cell from antibodies

Question 25

what occurs during the uncoating phase of viral replication?

Answer 25

cell lysozyme strip off virus protein coat, releasing viral genome

Question 26

what occurs during the synthesis of viral components phase of viral replication?

Answer 26

virus takes advantage of cell structures to replicate itself

Question 27

what occurs during the assembly phase of viral replication?

Answer 27

newly synthesised genome and proteins are assembled to form new virus particles

Question 28

what occurs during the release phase of viral replication?

Answer 28

viruses are released from host cell by sudden rupture or gradual extrusion through host membrane

Question 29

what virus causes herpes

Answer 29

herpes simplex virus

Question 30

what does oral herpes cause

Answer 30

sore throat and small blisters called cold sores

Question 31

what is the abbreviated name for oral-facial herpes simplex virus?

Answer 31

HSV-1

Question 32

how does the herpes virus reoccur in the form of a coldsore?

Answer 32

once initial infection has receded, the virus lies dormant in the trigeminal nerve

Question 33

name the 3 types of influenza

Answer 33

a,b and c

Question 34

name the 2 glycoproteins on the surface of the influenza virus

Answer 34

haemagglutinin (HA), neuroaminidase

Question 35

what is the differences between antigenic drift and antigenic shift in influenza viruses?

Answer 35

drift - minor changes, epidemics, a,b and c | shift - major changes, pandemic, only a

Question 36

how is herpes tested?

Answer 36

antibody gig test, DNA detection

Question 37

what causes CJD?

Answer 37

abnormal infectious proteins called prions

Question 38

do prions contain DNA or RNA?

Answer 38

no

Question 39

why is CJD untreatable?

Answer 39

prions cannot be destroyed by heat or radiation and there is no medication or treatment for them