Quiz 3 study guide

Question 1

How large are viruses

Answer 1

on the scale of nm’s

Question 2

Double stranded DNA virus example

Answer 2

Vericella-Zoster (Chicken pox/shingles)

Question 3

Single stranded DNA virus example

Answer 3

Parvovirus (like the dog virus, but the human strain)
Arthritis in adults

Question 4

Doble stranded RNA virus example

Answer 4

Rotavirus (#1 cause of severe diarrhea in children)

Question 5

Single stranded RNA virus example

Answer 5

Influenza virus
COVID-19 virus

Question 6

What do all viruses contain

Answer 6

a nucleic acid (some are RNA, some DNA, and some Single/double stranded)

Question 7

What is a capsid

Answer 7

a protein coat sourrounding a nucleic acid- inside of all viruses

Question 8

What is a capsomere

Answer 8

repeating protein subunits of the capsid

Question 9

What is an example of a helical capsid virus

Answer 9

tobacco mosaic virus (Helical= rod-shaped

Question 10

What is an example of a virus with a polyhedral capsid shape

Answer 10

Genital HPV (human papilloma virus)
- Common cause of cervical cancer

Question 11

What is the most common viral structure and symmetry

Answer 11

Isocahedron (Polyhedral)

Question 12

Complex shape example

Answer 12

bacteriophage (A virus that only infects bacteria)
Phage t4
Most are DS DNA viruses

Question 13

Where do you find complex capsids

Answer 13

in bacteriophages

Question 14

What is an envelope

Answer 14

a lipid bilayer membrane with virus-specific proteins that sourrounds the capsid of some viruses

Question 15

Where is the viral envelope derived from

Answer 15

host cell membranes

Question 16

Which virus has envelopes in every virus

Answer 16

influenza virus

Question 17

What are spikes

Answer 17

glycoproteins used by some viruses to attach to the host cell (Attaches virus to host cell)

Question 18

What does lysozyme do

Answer 18

perforates peptidoglycan, allow for nucleic acid insertion, useful for release after replication

Question 19

What are nucleic acid polymerases for

Answer 19

for RNA viruses

Question 20

What are neuraminidases

Answer 20

cleave glycosydic bonds in extracellular matrix, allow release

Question 21

List the life cycle of a bacteriophage (Phage lytic cycle)

Answer 21

1. Attachment, 2. Penetration, 3. Synthesis of nucleic acid and protein, 4. Assembly and packaging, 5. Release (lysis)

Question 22

What is the lysogenic cycle and steps

Answer 22

Induction, cell division, integration

Question 23

Lysogenized host cells are immune to what

Answer 23

reinfection by the same virus strain

Question 24

What are 3 viruses that do conversion (transduction) and create toxins

Answer 24

Diptheria toxin, botulinum toxin, cholera toxin (All bacteria, but create toxin by transduction)

Question 25

What replication always results in a dead host

Answer 25

lytic phage replication

Question 26

What replication results in a phage integrating its DNA into the bacterial chromosome

Answer 26

lysogeny

Question 27

How does release differ between phage and human viruses

Answer 27

Attachment and penetration, and release (Need to keep envelope intact in human virus b/c cannot just seperate)

Question 28

Difference between phage DNA and bacteria and Viron with human cells

Answer 28

Only Phage DNA enters bacterium, while the entire viron enters a human cell

Question 29

How does a phage release?

Answer 29

Always by lysis

Question 30

How does a human virus release?

Answer 30

Can release by lysis or budding

Question 31

How are viruses cultured in labs

Answer 31

1. Live animal hosts, 2. Embryonated eggs, 3. Cell Cultures

Question 32

Describe structure of COVID virus

Answer 32

Enveloped, single strand RNA, protein helical capsid

Question 33

Caliciviruses charachteristics

Answer 33

NOT enveloped, Norovirus, icosahedral, ssRNA

Question 34

Calicivirus diseases

Answer 34

Gastroenteritis, outrbreaks in care homes and cruise ships

Question 35

Transmission of Caliciviruses

Answer 35

Fecal-oral

Question 36

Pathogenesis of Caliciviruses

Answer 36

Relicate in small intestine epithelium, mucosal damage, loose digestive enzymes

Question 37

Herpesvirus charachteristics

Answer 37

dsDNA, enveloped, icosahedral

Question 38

Herpes transmission

Answer 38

Saliva, semen

Question 39

Coronaviruses charachteristics

Answer 39

ssRNA or dsRNA, spherical, helical, enveloped

Question 40

Retroviruses charachteristics

Answer 40

dsRNA, ssRNA, enveloped, icosahedral, truncated cone shape

Question 41

Diseases associated with retrovirus

Answer 41

HIV, HTLV 1/2

Question 42

Transmission of retroviruses

Answer 42

Musal route infection with CD4-positive cells, spread through body including CNS