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Flashcards in Chapter 13 Deck (56):
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Characteristic of viruses

Obligate intercellular parasite
Need host to multiple
Submicroscopic
Noncellular
Contain DNA or RNA
Protein coat
Lack enzymes for ATP

1

Louis Pasteur did what?

Coined term virus
Latin for poison

2

Iwanowski and Beijernick

Discovered tabacco mosaic virus

3

Low leaflet and frosch

Discovered foot and mouth disease in cattle

4

Structure of viruses

DNA or RNA not both
Single or double stranded
Needs to enter host
Protected by capsid

5

What's the capsid do?

Protein shell that surrounds nuclei acid

6

What is capsomere?

Sub unit of capsid that self assemble to form capsid

7

What is a naked virus mean?

No envelope

8

What is the envelope ?

Lipid structure that surround capsid

9

What are the spikes?

Project from envelope
Helps the virus adhere

10

Helical what is it??

Rod shape of the capsid

11

What is the polyhedral of the capsid?

20sided
3D appearance
Ex. Poliovirus, herpes, and adenovirus

12

What is the complex of the capsid

Capsid is polyhedral and contact tile sheath is helical
Ex. Bacteriophage and pox virus

13

What is the host range?

Spectrum of host cells a virus can infect
Depends on viruses requirement for multiplication
Must be chemically react with host receptors sites

14

What's does the capsid do of a t-even bacteriophage ?

Stores nucleic acid

15

What does the contractile sheath of a t-even bacteriophage?

Penetrates and inject nucleiac acid

16

What is the tail fiber of bacteriophage do?

For attachment

17

What do the structure of t even bacteriophage of tail pins?

Penetration of cell wall

19

What are the steps of the lyric cycle in T4 viruses ?

1. Attachment
2. Penetration/Entry
3. Biosynthesis
4. Maturation
5. Release

20

what is attachement?

uses the host cell's receptor sites (tail fibers)

21

what is penetration/entry?

Biral nucleic acid is injected into the host cell

22

what is biosynthesis?

each viral componet is made using host's metabolic machinery

23

what is maturation?

viral components are assembled

24

what is release?

bacteria cell is full of virues, lyses, and dies

25

what is burst time?

time it takes from attachemetn to release
average time is 20-40 min

26

what is burst size?

number of viruses released per host cell
average is 200 viruses

27

viral multiplication in bacteriophage?

multiply in two ways
lytic and lysongenic

28

lytic cycle cells

end with lyse (death to host cell)

29

lysogenic cycle allows

host cell to remain alive

30

lysogenic cycle

incorporates a viral nucleic acid into host cell's
phage remains inactive
everytime host replicate virues is

31

what is adverse conditions do to lysogenic cycle?

can cause the lysogenic cycle to end and lytic cycle to begin

32

what is the steps in lysogenic cycle?

1. attachment
2. pentiration/entry
3. prophage created
4. bacteria divides with prophage

33

what is prophage?

combination of bacterial and viral nucleic acids
if prophage begins outside of bacterial cells, virus will being lytic cycle

34

how do you grow bacteriophage in the lab?

1. mix bacteria and virus in a soft agar solution and pour onto plate with solid agar
2. incubate at 38 degrees celcius
3. lawn of bacteria with plaque will apear

35

what is plaque?

were virus has killed bacteria

36

what is the process for multiplication in animal viruses

1. attachment
2. penetration
3. uncoating
4. biosythesis and assembly
5. release

37

growing animal viruses in the lab

in live animal ;
some viruses can only exsist in animals
study the immune system response

38

growing animal viruses in embryonic eggs

viruses is injected into fertilized egg
viral growth is detected by death or damage to embryo
used to make vaccines

39

how do you identify viruses?

cytopahtic effects
serological tests
nucleic acids

40

what is serological tests?

detects antibodies against viruses in a patient

41

what is nucleic acids?

uses PCR to obtain enough nucleic acids to identify

42

taxonomy of virues
family
genus
species

family - virdae
genus - virus
species is common name of species

43

what are subspecies designated by?

number

44

example of taxonomy of viruses?

family ; herpesvirdae
genus; herpesvirus
species; human herpes virus
subspecies; HHV-1, HHV-2

45

what is adenovirdae?

common cold viruses

46

what is poxvirdae?

small pox or cow pox

47

what is orthomyxovirdae?

influenza viruses A, B, and C

48

herpesviridae?

cold sore, chicken pox

they are monoonucleosis

49

what is papvavirdae:

gential warts
cervic cancer

50

what is retrovirdae virus?

HIV

51

What are some extreme viruses?

ebola
causes fever, hemorrhaging and blod clotting

52

what is acute viral?

rapid onset of symptoms but not short lived
ex. influenza

53

what is latent viral infection?

virus remains asymtematic in host cell for long period of times
ex. cold sores and shingles

54

what is persistant viral infections?

disease occurs over long period of time
gennerally fatal
Ex. HIV/AIDS

55

what are ways to prevent viruses?

vaccines---> ex. rubella
antiviral drugs --> AZT

56

what is prions?

proteinaceous infection particles
cause neurolgical disease
Ex. Mad cow disease