Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > module 6 viruses > Flashcards

module 6 viruses Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are viruses

A

small non-cellular particles cannot replicate unless inside a living host
also called obligate intracellular parasite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 2 components that make up a virus

A

its genome and capsid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is specific about a virus genome

A

its either DNA or RNA
double or single stranded, circular, linear arrangement
size vary from few thousand to millions nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 types of large viruses

A

pandoravirus: 2.5 million nucleotides
megavirus: 1.25 million nucleotides
mimivirus: 1.2 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the structure of the capsid

A

membrane like protective structure- contains genetic material similar to nucleus of eukaryotic cells
either enveloped or non-enveloped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what makes up the envelope of the capsid

A

derived from host cell membrane and serves as additional barrier to external environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does it mean for a non-enveloped virus

A

virus surround by protein capsid: majority animal viruses are enveloped, plant viruses are not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is required for a virus to replicate

A

host cell enzyme in order successfully replicate
outside viruses lie dormant- have no active metabolism
must have a way into and a way to exit the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the general life cycle of a virus

A
  1. virus attach to host cell and envelope fuses w/membrane and open- release capsid into cytoplasm
  2. once nucleotide enter cytoplasm, it uncoat( unravel) release viral genome into cell
  3. new viral protein produce using host cell protein/enzyme and build new particles
  4. newly released virus ext the cell, infect additional cell in same environment or new one
  5. once new host is found, process of attachment repeats along with entry and replication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a bacteriaphage( phage)

A

virus that infects a bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the structure of a bacteriophage

A 
have icosahedral( 20 sided polygon) capsid head group and helical tail and fibers( legs aid in bind to host)
structure not seen to infect human/plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does bacteriophage get into a cell

A

Does not pass capsid into host cell
tail fibers mediate binding, helical tail penetrate host cell wall
viral genome injected into cytoplasm through helical tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are 2 forms of replication

A

lytic and lysogenic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe lytic bacteriophage

A

replicate in host bacteria until it lyses destroying host bacterial cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe Lysogenic bacteriophage

A

Lysogenic bacteriophage can exist in non-replicative state so viral genome integrate in host genome
host cell replicates DNA as well as viral DNA
production of viral protein via transcription and translation is suppressed
stress can cause reactivation of replication of viral protein and re-enter lytic replication cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a prophage

A

lysogenic bacteriophage that has integrated into host genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a viral titer and how is this important for research

A

amount of virus in culture
allow research to carefully and effectively plan infection experiments
too much virus: overwhelm and kill host
too little virus: take too long to grow new virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Rubella

A

German Measles
virus is linear, single stranded, enveloped, RNA, 10-12,000 nucleotides
belong to Togaviridae family

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is Rubella transmitted

A

air borne particles: caught of infected patient
Pt is infectious 1 week before and after appearance of rash
eventually multiplies in upper respiratory and conjunctiva of the eye: travels from eye to GI, urinary tract, skin and CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are Sx of Rubella

A

fever, flu like, conjunctivitis, red skin rash: trunk first then rest of the body
can be transmitted to fetus in pregnant women: cause damage to fetus eyes, ears, heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Is Rubella preventable

A

yes: vaccine obtained about age 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is Mumps

A

Epidemic Parotitis
linear, single stranded, enveloped RNA 15,000 nucleotides
belong to Paramyxovirus family

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is Mumps transmitted

A

transmit air borne droplets from infected individual

highly contagious- 7 days prior and 8 days after Sx show

24
Q

What are the Sx of Mumps

A

cold: headache, fever, muscle ache, painful swelling of salivary parotid gland
swelling can occur in teste/ovaries and pancreas

25
Q

Is Mumps preventable

A

yes with vaccine: MMR

26
Q

What is chicken pox

A

Varicella Virus: Zoster Virus
linear stranded- single, enveloped, DNA, 125,000 nucleotides long
Herpesvirus family

27
Q

How is chicken pox characterized

A

small itchy fluid filled blisters on any part of the body

highly contagious

28
Q

How is chicken pox transmitted

A

contagious 1-2 days before rash appear and considered non-contagious when scabs form over blisters
contact with blisters
airborne droplets

29
Q

Where does chicken pox virus remain

A

dormant in body

can reappear as shingles about age 60

30
Q

What is shingles

A

Herpes Zoster: reactivate of VZV

31
Q

How is shingles characterized

A

painful blisters as VZV lies inactive in nerves

blister localized and limited to small area

32
Q

What are the Sx of shingles

A

first: severe pain, tingling, burins, where rash presents later
once blisters form: possible to transmit virus to someone who has not had chicken pox or VZV vaccine

33
Q

What is Tx for shingles

A

mild sx: over the counter pain meds

painful blisters: can get anti-viral drug acyclovir

34
Q

What is small pox

A

vanilla virus
has been eradicated
linear, double stranded, enveloped DNA virus 186,000 nucleotides

35
Q

What are the 2 variants of small pox

A

variola major: more severe and most common

variola minor:

36
Q

How is small pox transmitted

A

transmits easily through air and direct contact

37
Q

What are the Sx of small pox

A

high fever, rash in mouth/throat, rash appear externally face and then spread to arm/legs, hands and feet
Rash: raised bumps filled with opaque fluid eventually form scabs: once fall off leave more resemble pitted scar

38
Q

When was vaccine developed for small pox

A

1796

is first infectious disease to be eradicated

39
Q

What is Polio

A

Poliomyelitis
single stranded, non-enveloped RNA 7700 nucleotides
Picornaviridae family
30 nm in diameter: most significant small virus

40
Q

How is polio characterized

A

when infected, enters CNS, replicate damage motor neurons

infected neurons are found in spinal cord, brain stem or motor cortex: causes temporary or permanent paraylsis

41
Q

Is there a vaccine for polio

A

yes: developed in 1955- Johnas Stakle- 90% individual developed protective antibodies
oral vaccine developed in 1961
both vaccines 95% effective in forming preventative antibodies

42
Q

What is influenza

A

Orthomyxoviridae family
single stranded, enveloped RNA 50-120 nm
3 subtypes: A, B, C

43
Q

Which subtype of influenza is most pathogenic

A

A

44
Q

What are the 2 glycoproteins in the viral envelope of influenza

A

HA: hemagglutinin: involved in entry of viral particle into host cell: 16 subtype
N: neuraminidase: involved in budding and release of new viral particle from host cell: 9 subtype

45
Q

What are the targets when building influenza vaccine

A

HA and N
can appear in any combo and is not seen on every iron
naming is based on which protein on envelope

46
Q

How was the flu in 2009 and the Asian flu in 1957 named

A

H2N2: asian
H1N1: 2009

47
Q

What is HIV

A

Human Immunodeficiency Virus
Retroviridae family
linear, single-stranded enveloped 10,000 nucleotides

48
Q

Describe structure of HIV

A

2 copies single stranded linear RNA enclosed by capsid
surrounding 2 RNA strand is cone shape capsid with 2000 copies viral protein p24
viral envelope is derived from cell host membrane surrounds viral capsid

49
Q

What is in the viral envelope of HIV

A

2 key glycoprotein: gp120 and gp41

50
Q

How does HIV enter host cell

A

viral gp120 protein bind to host protein CD4, allows gp41 to bind to host chemokine receptor CXCR4 or CCR5

51
Q

What happens after HIV has entered and finished uncoating

A

HIV protein reverse transcriptase acts on RNA= complementary DNA
Now double DNA transport to nucleus and integrates into host genome

52
Q

What happens after integration of HIV in host genome

A

virus rely primarily on host cell machine( envelope/ transcript) for replication
once replicated: new virus assembled and released from ell to infect neighbor cells

53
Q

What is the Tx for HIV

A

anti-retroviral meds: combat virus reproduction

if go untreated: turns to AIDS

54
Q

What is AIDS

A

Acquired Immunodeficiency Syndrome

55
Q

How is AIDS characterized

A

severe loss of body immunity: individual does not die from aids but other complications because of low immunity
35 million people have died and 37 million cases of HIV

Microbiology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions