Chap 13- Animal Viruses

Question 1

Bacteriophages and animal viruses have similar mechanisms of attachments to host cells,

Answer 1

both have appendages to attach to receptors on host cell’s plasma membrane. (animal viruses have spikes)

Question 2

Multiplication of Animal Virus (APUBMR)

Answer 2

ATTACHMENT- viral N.A attaches to host cell wall, PENETRATE- virus entire nucleocapsid enters host cell via endocytosis or fusion; UNCOATING- protein separates from N.A in virion pre replication; Biosynthesis- production of N.A & proteins; MATURATION- components (DNA & proteins from cytoplasm in nucleus) assemble RELEASE- by budding (enveloped) or burst/rupture

Question 3

In animal viruses, penetration mechanism into host cell depends on?

Answer 3

Whether virion is enveloped or non enveloped

Question 4

NAKED, NON ENVELOPED virions enter host cell via ______

Answer 4

Endocytosis- host cell membranes cave in forming vesicle that surrounds virion

Question 5

ENVELOPED virions enters host cells via ______

Answer 5

fusion with host membrane (virion envelope fuses to host cell membrane)

Question 6

Attachment sites on virions ______? Attachment sites on host cell plasma membranes _____?

Answer 6

Spike; Receptor Sites

Question 7

process where release of nucleic acid from capsids(proteins) done prior to replication; carried out by enzymes

Answer 7

uncoating

Question 8

Virus Replication Process is aka

Answer 8

Biosynthesis

Question 9

How does viral DNA get to make copies of themselves?

Answer 9

They force host eukaryotic cells into S phase of mitosis

Question 10

occurs during interphase, and is responsible for replication of DNA

Answer 10

S-phase

Question 11

Animal viruses can either be __________ , while bacteriophages can only be _______ ?

Answer 11

RNA OR DNA; DNA ONLY

Question 12

How many strands does Animal Virus DNA have?

Answer 12

It can either have Single strand of DNA or Double strand of DNA (replication usually happens in nucleus)

Question 13

Animal Viruses- Replication of DNA takes place ______? Biosynthesis of proteins take place _____?

Answer 13

nucleus; cytoplasm

Question 14

process where completed DNA virion is transported from nucleus to cell membrane for it to EXIT via budding or lysis

Answer 14

RELEASE (animal virus DNA rep)

Question 15

WHat forms do RNA virus come in?

Answer 15

SINGLE STRANDED or DOUBKE STRANDED

Question 16

SINGLE STRANDED RNA can present in 2 forms;

Answer 16

SENSE STRAND- (+)RNA or ANTISENSE STRAND (-)RNA

Question 17

this strand acts as mRNA

Answer 17

(+)RNA sense strand

Question 18

this strand acts as template for (+)RNA

Answer 18

(-)RNA antisense strand

Question 19

RNA replication is only done by ______?

Answer 19

viruses

Question 20

Where does biosynthesis and maturation occur during RNA replication?

Answer 20

Cytoplasm

Question 21

RNA viruses that use their viral RNA as a template for DNA “reverse transcription”

Answer 21

retrovirus (process carried out by reverse transcriptase)

Question 22

viral DNA created from viral RNA gets incorporated into host chromosome and becomes a ______

Answer 22

provirus

Question 23

the virus never comes out of chromose and is protected from host’s immune system

Answer 23

provirus

Question 24

infection w/ rapid onset; short duration; immune system gradually eliminates virus

Answer 24

ACUTE infection

Question 25

continues for years/ lifetime; may or may not present symptoms

Answer 25

Persistent infection

Question 26

Can viruses be both acute and persistent?

Answer 26

YES

Question 27

continuous production of low level viral particles that lack symptoms but still transmit virus

Answer 27

chronic

Question 28

infection where viral genome remains silent in host but can become reactivated to produce infection

Answer 28

Latent

Question 29

Chronic infection examples

Answer 29

Hep B & Hep C; HIV is mixed

Question 30

Latent infection example

Answer 30

Herpes; Epstein Barr; CMV & shingles of Herpes fam

Question 31

silent viral genome in latent infections is know as

Answer 31

provirus

Question 32

mutation of proto-oncogene that has been changed to promote uncontrolled growth

Answer 32

oncogene (some viruses can carry this gene) HPV

Question 33

How does a virus get to carry oncogene?

Answer 33

Provirus disrupts proto oncogene and causes chronic damage to DNA resulting in inflammation