CSIM 1.16 - Case 40: Spotty Problem

Question 1

Define virus?

Answer 1

Submicroscopic entity consisting of a nucleic acid (single) surrounded by a protein coat
Nucleic acid = (DNA or RNA) - (double stranded or single stranded)

Question 2

In terms of viral structure what is the capsid and what is its function?

Answer 2

Protein coat surrounding the viral DNA/RNA
It may have protein spikes (H and N)
Provides structural integrity and protection from degradation

Question 3

In terms of viral structure what is the lipid envelope and what is its function?

Answer 3

Some viruses have a lipid envelope (HSV/Measles)
They acquire this from cell membranes
Contains proteins required for viral attachment to a new cell for infection

Question 4

Where does viral replication occur?

Answer 4

Only capable of replication within plant/animal cells

Question 5

Name the stages of a viral life-cycle?

Answer 5

Attachment
Entry
Replication and protein synthesis
Assembly
Release

Question 6

Describe the Baltimore classification for viruses?

Answer 6

Double stranded DNA (most common)
Single stranded RNA (most common)
Single stranded DNA
Double stranded RNA
Single stranded RNA + Reverse transcriptase

Question 7

In human DNA replication and protein synthesis - how is double stranded DNA converted into mRNA?

Answer 7

RNA polymerase

Question 8

In human DNA replication and protein synthesis - how is double stranded DNA replicated?

Answer 8

DNA polymerase

Question 9

Name three viral families that contain double stranded DNA?

Answer 9

Herpes viridae
Adenoviridae
Papovaviradae

Question 10

Name two viral families that contain single stranded RNA (Negative sense)?

Answer 10

Orthomyxoviridae

Paramyxoviridae

Question 11

Name two viral families that contain single stranded RNA (Positive sense)?

Answer 11

Picornaviridae

Hepaciviridae

Question 12

Name a viral family that contains single stranded DNA?

Answer 12

Paroviridae

Question 13

Name a viral family that contains double stranded RNA?

Answer 13

Rotaviridae

Question 14

Which three specific enzymes are required for retroviruses to be effective in replication in host cells?

Answer 14

Reverse transcriptase
Integrase
Protease

Question 15

In the attachment phase of HIV life-cycle - which receptor does HIV bind to and which drug blocks this interaction?

Answer 15

CD4 receptors

Maravirol blocks attachment of HIV to CCR5 (cellular co-receptor)

Question 16

What does the drug Aciclovir do?

Answer 16

Inhibits DNA polymerase of herpes simplex virus

Question 17

What do the drugs Tenofovir and Eravirenze do?

Answer 17

Inhibit reverse transcriptase in HIV

Question 18

What does the drug Raltegravir do?

Answer 18

Inhibits integrase enzyme in HIV preventing the incorporation of viral DNA into host chromosomes

Question 19

What does the drug Darunavir do?

Answer 19

Inhibits proteases in HIV preventing the cleaving of large poly-proteins into smaller active viral proteins

Question 20

What do the drugs Tamiflu and Oseltamivir do?

Answer 20

Neuraminidase inhibitors - prevent the virus from ‘un-docking’ the infected cell