Tortora Micro Ch.13 Part B Viruses

Front 1

Viruses must be grown in what?

Back 1

Living cells

Front 2

What is the easiest type of virus to grow?

Back 2

Bacteriophage (complex virus)

Front 3

What method is used to count viruses on a solid medium?

Back 3

Plaque method

Front 4

What is the area of lysis within the solid medium called?

Back 4

Plaque

Front 5

What is a single plaque area called?

Back 5

Plaque-forming units (PFUs)

Front 6

Cultivation of some animal viruses requires what?

Back 6

Whole animals (mice, rabbits, guinea pigs, etc)

Front 7

Besides whole animals, what is another thing that is used to cultivate animal viruses?

Back 7

Chicken embryos (eggs)

Front 8

What is used to cultivate many vaccines like the Flu vaccine?

Back 8

Chicken embryos (eggs)

Front 9

What is the most common method of growing viruses today?

Back 9

Cell cultures

Front 10

What are 3 ways of cultivating viruses?

Back 10

1. Whole animals
2. Chicken embryos (eggs)
3. Cell cultures

Front 11

What are 2 ways of identifying viruses?

Back 11

1. Serological test
2. Nucleic acid finger prints

Front 12

Which test is used more often to identify viruses?

Back 12

Serological test

Front 13

Do viruses contain enzymes?

Back 13

No, viruses do not contain enzymes for energy production or protein synthesis

Front 14

True or False:

Some viruses are capable of protein synthesis

Back 14

False - No viruses are capable of protein synthesis

Front 15

In order for viruses to multiply, what must it do?

Back 15

Invade a host cell and redirect the hosts METABOLIC MACHINERY to produce viral enzymes and components.

Front 16

What are 2 types of reproduction that viruses exhibit?

Back 16

1. Lytic cycle
2. Lysogenic cycle

Front 17

What happens during the lytic cycle?

Back 17

Phage causes the lysis and death of a host cell; virus injects nucleic acids within host, creates components, replicates, and lysis

Front 18

What happens during Lysogenic cycle?

Back 18

Phage injects nucleic acids within host and the acids are incorporated within the DNA (prophage) of the host.

Front 19

What is a prophage?

Back 19

When the viral nucleic acids combine with the host DNA.

Front 20

What is lysogeny?

Back 20

Infected host cell that contain prophages (inactive).

**prophages are viral nucleic acids that are incorporated into the host cell DNA

Front 21

What can potentially be initiated to lysogenous cells?

Back 21

Lytic cycle

Front 22

What 2 components or factors can lead to the excision of the prophage and initiate the lytic cycle?

Back 22

1. Mutagens
2. Spontaneous events (recombination)

Front 23

A lysogenic host cell can transfer bacterial genes through what?

Back 23

Transduction

Front 24

Besides the inevitable lytic cycle of lysogenic host cells, phage genes also assist in what for bacteria?

Back 24

Virulence

Front 25

What is "burst time"?

Back 25

Time from phage absorption to release (20 to 40 min).

Front 26

How long can burst time take?

Back 26

20 to 40 min

Front 27

What is "burst size"?

Back 27

The number of newly synthesized phages produced from a single infected cell (50 to 200 or more viral particles).

Front 28

How many phages can be produced during burst size?

Back 28

(50 to 200+)

Front 29

What bacteria is found on meat and poultry products that infected 2,500 people (500 deaths)?

Back 29

Listeria monocytogenes

Front 30

What is used to kill of Listeria monocytogenes within meat and poultry products?

Back 30

6 types of bacteriophages

Front 31

What is seen on meat and poultry packages when it has been treated with viral food additives to kill of Listeria monocytogenes?

Back 31

"Bacteriophage Preparation"

Front 32

What are animal viruses called?

Back 32

Retrovirus

Front 33

What is the family that Retroviruses belong to?

Back 33

Retroviridae

Front 34

What type of viruses are Retroviruses?

Back 34

Enveloped viruses with RNA genome

Front 35

When a Retrovirus enters an animal host cell and uncoats the nucleic components, what happens next?

Back 35

The "reverse transcriptase" performs reverse transcription from RNA to double helix DNA

Front 36

When a Retrovirus performs reverse transcription within the animal host cell, what happens next?

Back 36

Viral ds/ss DNA is incorporated into the host DNA with the help of the integrase enzyme

Front 37

What enzyme is used to help integrate viral DNA into host DNA?

Back 37

Integrase enzyme

Front 38

What enzyme from the Retrovirus is used within a host cell to perfrom revers transcription?

Back 38

Reverse transcriptase

Front 39

What are the steps to animal replication?

Back 39

1. Attachment
2. Penetration via endocytosis (phagocytosis)
3. Uncoating of capsid
4. Viral genome replication (RNA to ds/ss DNA)
5. Synthesis of both DNA
6. Release of viruses (lysis or budding)