Viruses

Question 1

What is meant by “viruses are acellular”?

Answer 1

They need another organism to survive

Question 2

Viruses come in a variety of shapes but the individual subunits are identical. True or false?

Answer 2

True

Question 3

Do viruses generate ATP?

Answer 3

No

Question 4

What does the structure of a virus consist of?

Answer 4

Protein coat (capsid)

Question 5

The capsid is composed of __________

Answer 5

capsomeres

Question 6

What are the two geometrical forms of a virus?

Answer 6

Icosahedral

Helical

Question 7

Do all viruses have envelopes and tails?

Answer 7

No, some do, some don’t

Question 8

Viruses only have one type of nucleic acid. What can this be?

Answer 8

ssDNA or dsDNA OR

ssRNA or dsRNA

Question 9

How can viral replication be observed?

Answer 9

Observe host lysis (plaque formation)

Question 10

For viruses to replicate, they require a host. True or false?

Answer 10

True

Question 11

What are the routes of transmission for viruses?

Answer 11

Respiratory transmission
Faecal-oral transmission
Blood-borne transmission
Sexual transmission
Animal or insect transmission

Question 12

Some viruses have affinity to specific tissues. True or false?

Answer 12

True

Question 13

CD4+ cells are infected by ____

Answer 13

HIV

Question 14

What happens when cells are infected by a virus?

Answer 14

Cell destruction
Virus-induced changes to gene expression
Immunopathogenic disease

Question 15

How is influenza A virus spread?

Answer 15

Respiratory route

Question 16

Influenza A alters cytokine expression, leading to fever. True or false?

Answer 16

True

Question 17

Are antivirals able to enter cells infected with a virus?

Answer 17

Yes

Question 18

How do antivirals work?

Answer 18

They interfere with viral nucleic acid synthesis and/or regulation

Question 19

Antiviral drugs are used to treat infections caused by viruses including HIV. True or false?

Answer 19

False - treat infections caused by viruses other than HIV. Antiretroviral drugs are used to treat infections caused by HIV

Question 20

Why is amantadine a narrow spectrum drug?

Answer 20

Only works against Influenza A

Question 21

Amantadine is used prophylactically when a vaccine is not available. True or false?

Answer 21

True

Question 22

Taking amantadine doesn’t stop you from getting an infection, it just reduces your recovery time. True or false?

Answer 22

True

Question 23

Aciclovir suppresses the replication of which viruses?

Answer 23

HSV1
HSV2
VZV (Varicella)

Question 24

Oseltamivir and Zanamivir are active against which types of influenza?

Answer 24

A and B

Question 25

What are High Active Antiretroviral Drugs?

Answer 25

Include at least three medications which work in different ways to reduce the viral load

Question 26

What are the three different types of TSEs?

Answer 26

Infectious Sporadic Familial

Question 27

What are the characteristics of TSEs?

Answer 27

transmissible relentlessly progressive and inevitably fatal long incubation periods no antibody response no fever (afebrile) neuronal vacuolation (plaques in the brain)

Question 28

Prions are larger than viruses. True or false?

Answer 28

False - smaller

Question 29

What is the normal protein in a prion?

Answer 29

PrPc - found at the cell surface in plasma membrane

Question 30

The normal protein of a prion is easily soluble and easily digested by proteases. True or false?

Answer 30

True

Question 31

The secondary structure of a normal protein of a prion is dominated by beta conformation. True or false?

Answer 31

False - alpha helices

Question 32

What is the abnormal protein of a prion?

Answer 32

PrPsc

Question 33

What is the difference between a normal and abnormal protein in a prion?

Answer 33

The secondary structure in an abnormal protein is dominated by beta conformations whereas in a normal protein it is dominated by alpha helices

Question 34

What is a similarity between a normal and abnormal protein in a prion?

Answer 34

They have the same amino acid sequence and primary structure

Question 35

What happens when a PrPsc contacts a PrPc?

Answer 35

It converts it into the abnormal form

Question 36

The abnormal protein is easily digested by proteases. True or false?

Answer 36

False - highly resistant

Question 37

What are the two different types of atypical BSE prions?

Answer 37

H-type | L-type