Chapter 8 (from quizlet)

Question 1

Host specificity of a virus is determined by what?

Answer 1

interactions between viral attachment proteins and host cell receptors

Question 2

What binding determines the ability of a virus or bacteriophage to specifically attach to a host cell occurs through the interactions of the viral attachment protein with the host cell receptor?

Answer 2

the host range

Question 3

Antiviral drugs that act at the level of host recognition are designed to do what?

Answer 3

prevent virus binding to the cell receptor

Question 4

HIV enters the cell through what type of mechanism?

Answer 4

membrane fusion

Question 5

the influenza virus gains entry into a host cell how?

Answer 5

by receptor-mediated endocytosis

Question 6

How do plant viruses often gain entry into host cells?

Answer 6

by injury caused by insects to host cells

Question 7

What is the mode of action for fuzeon? (an antiviral drug that prevents membrane fusion for entry into the cell by HIV)

Answer 7

to bind to gp41 membrane fusion protein of HIV

Question 8

The Baltimore classification scheme classifies viruses based on their mechanism of mRNA synthesis in how many classes?

Answer 8

7

Question 9

Class I viruses, double-stranded DNA viruses, usually utilize what polymerases for mRNA synthesis of DNA replication?

Answer 9

host cell DNA-dependent RNA polymerase and host cell DNA-dependent DNA polymerase

Question 10

Class III viruses, double-stranded RNA viruses, utilize what polymerase for genome synthesis?

Answer 10

viral RNA-dependent RNA polymerase

Question 11

Class V viruses, negative sense-stranded RNA viruses, utilize what polymerase for mRNA synthesis?

Answer 11

viral RNA-dependent RNA polymerase

Question 12

For most double-stranded DNA eukaryal viruses, DNA replication occurs in the ___ and translation occurs in the ____.

Answer 12

nucleus, cytoplams

Question 13

A bacteriophage genome that is integrated into the bacterial chromosome is called what?

Answer 13

a prophage

Question 14

Phage lambda is referred to as a temperate phage. What is a temperate phage?

Answer 14

A phage that can undergo either a lytic or lysogenic phase of replication.

Question 15

Protease inhibitors are routinely used in the treatment of an HIV infection to slow down the progression of the disease..How do these inhibitors work?

Answer 15

They inhibit the proteolytic modification of the viral capsid to form an infectious virion

Question 16

How do most enveloped viruses exit the cell?

Answer 16

by budding

Question 17

What is the method of assembly of the intact virion of the tobacco mosaic virus?

Answer 17

the capsid proteins assemble around the viral nucleic acid

Question 18

Bacteriophage T4 lyses the bacterial host cell for release of newly formed virions. The cell wall of the bacterium is broken down by this virally encoded enzyme..

Answer 18

lysozyme

Question 19

Many antiviral drugs are nucleoside analogs. The nucleoside analogs primarily target what enzyme?

Answer 19

viral nucleic acid polymerases

Question 20

AZT is a nucleotide analog used to treat people infected with what?

Answer 20

HIV

Question 21

The viral attachment protein specifically binds to a host cell receptor. What are examples of host cell receptors?

Answer 21

proteins, glycoproteins, lipopolysacchardes, sialic acids

Question 22

The second step in viral replication is entry. What is the entry for bacteriophage?

Answer 22

direct entry of the nucleic acid into the cell

Question 23

Class VII viruses, double-stranded DNA viruses that utilize reverse transcriptase, replicate the genome using what polymerase?

Answer 23

host cell DNA-dependent RNA polymerase

Question 24

What is the reason nucleoside analogs are effective against viral nucleic acid polymerases?

Answer 24

because viral polymerases have a high affinity for incorporation of the analogs

Question 25

The enzyme ___ has a high affinity for AZT and will incorporate it into a newly synthesized DNA strand. This effectively terminate DNA replication because the incoming nucleotide cannot be bound to AZT.

Answer 25

viral reverse transcriptase

Question 26

An HIV mutant has been identified that is resistant to the drug AZT. most likely the mutation occurred in the viral gene that encodes for what?

Answer 26

reverse transcriptase