Introduction to Virology

Question 1

What happened on May 14, 1796?

Answer 1

Edward Jenner used cowpox from milkmaid Sarrah Nemes to vaccinate 8 yr old James against smallpox

Question 2

1970

Answer 2

David Baltimore and Howard Temin discover reverse transcriptase and retroviruses

Question 3

1980

Answer 3

Smallpox eradicated

Question 4

1983

Answer 4

HIV defined as the cause of AIDS

Question 5

Arbovirus

Answer 5

Older term for AR-thropod BO-rne virus

• includes bunyaviridae, togaviridae, and orbiviruses and rhabdoviruses
• many viruses transmitted by insects are not considered arboviruses

Question 6

Bacteriophage

Answer 6

Virus parasitizing bacteria

Question 7

Capsid

Answer 7

Protein coat of a virus

Question 8

Capsomere

Answer 8

Individual structural proteins that collectively make up the capsid

Question 9

Defective interfering particle

Answer 9

Virus particle having a capsid, but an incomplete nucleic acid content, or an empty particle, which interferes with replication of complete particles

Question 10

Envelope

Answer 10

Phospholipid covering derived from host cell membranes, either nuclear or cytoplasmic (plasma membrane or endoplasmic reticulum) present on some viruses

Question 11

Icosahedron

Answer 11

Polyhedral shape composed of 12 vertices (corners) and 20 triangular faces
- icosahedron nucleocapsids are said to be of cubic symmetry

Question 12

Nucleocapsid

Answer 12

Structural term denoting the combined nucleic acid and capsid
- may be helical or cubic in symmetry

Question 13

Orphan virus

Answer 13

Virus isolated in the absence of disease

- virus not associated with a disease (can be species specific)

Question 14

Peplomere

Answer 14

Glycoprotein subunit projecting from the envelope referred to as “spikes” that function in attachment to host cells

Question 15

Prions

Answer 15

Unconventional agents of disease resulting in spongiform encephalopathies by proteins that cause protein folding anomalies

• ex: bovine spongiform encephalopathy, scrapie, kuru
• highly regulated
• intermediate hosts allow for zoonotic transmission

Question 16

Translation

Answer 16

Process by which base sequences in mRNA produce specific amino acid sequences in a protein

Question 17

Transcription

Answer 17

Process of forming mRNA from nucleic acid, not necessarily DNA

Question 18

Virion

Answer 18

Individual viral particle

Question 19

Viriods

Answer 19

Class of infectious agents, occurring in plants that are smaller than viruses and consist of short strands of RNA without a capsid

Question 20

Virus

Answer 20

Complex molecular particle, capable of infecting cells and causing disease by redirecting host cellular synthetic machinery towards the synthesis of new infectious particles
- composed of nucleic acid (DNA or RNA, but not both), proteins, and sometimes lipids and carbs in the form of glycoproteins

Question 21

What is the main driving force of evolution?

Answer 21

Viruses

Question 22

All viruses are _______

Answer 22

Endogenous

Question 23

Are functional viral proteins part of the viral structure?

Answer 23

No, just induce change in the host

Question 24

What is the rate limiting step in protein transcription?

Answer 24

RNA

- half life is in microseconds

Question 25

All viruses that carry RNA are _______

Answer 25

Negative sense | - if they are positive sense, then they are coded for by that virus

Question 26

DNA viruses - replication enzymes

Answer 26

Are all DNA dependent, DNA polymerase | - herpes, adeno, papova, and parvo are coded for by the host cell. all others are coded for by the virus

Question 27

RNA viruses - replication enzymes

Answer 27

Are mostly RNA dependent, RNA polymerase - retro is RNA dependent, DNA polymerase (RT) - bunya, orthomyxo, paramyxo, rhabdo, reo, retro, and arena are all carried by virus

Question 28

What DNA virus replicates in the cytoplasm?

Answer 28

Poxvirus

Question 29

What RNA viruses replicate in the nucleus?

Answer 29

Paramyxo and retroviruses

Question 30

What viruses are more diverse, due to lack of proofreading steps?

Answer 30

RNA viruses