Virus

Question 1

Shared with Human DNA

Answer 1

40% human DNA is viral dna

Question 2

Cellular reservoir

Answer 2

Survival (mechanism to propagate, haven from environment)
Recombination
Evolution

Question 3

Features

Answer 3

Not visible
not culturable
not removed by filtration
not complex
not treatable with antibiotics
small
acellular
simple construction
core nucleic acid
viral structure 
envelope

Question 4

Viruses only

Answer 4

multiply inside cells
can infect bacteria
DNA or RNA not both
metabolically inert
hijack cells
dormant phase (provirus)
Protein capsid
Attachement
Envelope
Lipid bilayer from the host

Question 5

HIV

Answer 5

envelope proteins
outer lipid from host
viral RNA
core proteins
capsid inside

Question 6

Envelope

Answer 6

camouflage from immune system
Attachement and entry into cells
more complex envelopes are more sensitive to damage

Question 7

Naming system

Answer 7

Modern- genome sequence
Disease- HIV TMV
Bacterial Virus- Sigla Code
By shape

Question 8

Fillamentous viruses

Answer 8

Rod shape
TMV, Ebola
central cone surrounded by protein capsid
helical symmetry
sapsomere- indue. protein unit surround RNA in helix

Question 9

Icosahedral viruses

Answer 9

appear spherical
central core surrounded by 20 side protein capsid
more complex
3 axis of summetry
complex strength

Question 10

Nucleocapsid

Answer 10

Core and Capsid

Question 11

Complex animal viruses

Answer 11

nucleocapsids surrounded w/ envelopes

Question 12

complex bacteriophage

Answer 12

icosahedral head
multicomponent tail- attach and penetrate
large genomes code for proteins and assembly

Question 13

Replication

Answer 13

APUSAR

Question 14

Replication

Adsorbtion

Answer 14

attachment of iron to host
specific host cell receptors
depends on chance

antibodies bind and prevent this step

Question 15

Replication

Penetration

Answer 15

entry into host cell
plant viruses enter at sites of damage
animal viruses enter by endocytosis or fusion
bacteriophages require mechanism

Question 16

Replication
Penetration
BACTERIOPHAGE

Answer 16

Tail fibres attach
tail sheets contracts, carries 144 ATP
rigid tail core hollow spike driven through envelope
DNA enters

Question 17

Replication

Uncoating

Answer 17

decapsidisation

uncoats in cytoplasm by host cell proteases

Question 18

Replication

Synthesis

Answer 18

Transcription and translation
control protein and inhibits cell expression
replicase: new copies
structural: capsid

Viral?
DNA viruses use host enzymes, RNA uses iron enzymes
Retrovirus: RNA → DNA → Transcribed
ssRNA acts like mRNA

Question 19

Replication

Assembly

Answer 19

Spontaneous

• economy of effort
• error check

Complex

• requires several capsid subunits
• requires scaffolding proteins

Question 20

Replication

Release

Answer 20

Host cell dies, iron released
or in bacteria, viral lysosome bursts
enveloped viruses bud through membrane

REMEMBER, some viruses become latent and may insert its genome into host genome (provirus)

Question 21

Antivirals

Answer 21

Antireplication strategy and vaccinate

Question 22

Herpes Simplex

Answer 22

HS1
HS2
Varicella Zoster Virus VZV (chickenpox)
Epstein Barr Virus EBV 
Cytomegalovirus CMV

Question 23

Differences in Herpes

Answer 23

ā wide host range, short life cycle
SENSORY GANGLIA

B restricted range, long life cycle
SECRETORY AND KIDNEY

y narrow range
LYMPHOCYTES