Brainscape's Knowledge GenomeTM

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


See full index

biology topic 2 (cells and viruses) > viruses > Flashcards

viruses Flashcards

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

how much times smaller are viruses than bacterium

A

50 times smaller

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

defenition of viruses

A

-not cells
-arrangemnts of genetic material and protein that invade other living cells and take over their biochemistry to make more viruses

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

obligate intracellular parasites

A

they can only exist and reproduce as parasites in the cells of other living organisms

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

envelope

A

coat around virus cell derived from lipids of host cell

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

capsid

A

protein coat is made up of simple repeating protein units

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

capsomeres

A

repeating protein units that make up capsids

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

benefits of using repeating units as capsomeres

A

-minimises the amount of genetic material needed to code for coat production
-makes protein coat simple as possible

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

benefits of having a lipid envelope

A

easier for viruses to pass from cell to cell

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

negatives of having a lipid envelope

A

vulnerable to substances such as ether which can dissolve lipid membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are antigens also know as

A

virus attachment particles

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

how do viruses attach to host cells

A

by VAPs that target the cells surface memrbane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how are viruses classified

A

-by their genome and mode of replication

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

whats the genetic material in DNA viruses

A

DNA

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

what does the DNA do in DNA viruses

A

acts as template for new viral DNA and for mRNAs needed to induce synthesis of a viral protein

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

examples of DNA viruses

A

small pox
adenoviruses

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

examples of a bacteriophage

A

lambda phage

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

what are bacteriophages

A

viruses which infect bacteria

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

genetic material of RNA viruses

A

RNA

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

do DNA or RNA viruses mutate more

A

RNA

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

ssRNA

A

RNA viruses with a single strand of RNA

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

positive ssRNA

A

-positive sense RNA
-have RNA that can directly act as mRNA and be translated at the ribosomes

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

examples of plant and animal diseases caused by positive ssRNA

A

tobacco mosaic virus
SARS
polio
hepatitis C

23
Q

negative ssRNA

A

-negative sense RNA
-cant be directly translated

24
Q

what must happen to negative ssRNA before it can translate

A

it must transcribe

25
Q

examples of diseases caused by negative ssRNA

A

measeles
influenza
ebola

26
Q

what do RNA retroviruses have structurally

A

lipid envelope and protein capsid

27
Q

reverse transcriptase

A

enzyme synthesised in life cycle of retrovirus that makes DNA molecules corresponding to viral RNA genome

28
Q

what happens to DNA made by reverse transcriptase

A

incooparated into the host cell DNA and used as a template for new viral proteins new RNA viral genome

29
Q

example of retrovirus

A

HIV

30
Q

how do bacteriophages infect host cell

A

inject genome into host cell but bulk of genome remains outside cell
viral DNA forms capsid or plasmid around bacterium

31
Q

endocytosis

A

host cell digests capsid revealing viral genome

32
Q

most common way of virus entering host cells

A

viral envelope fuses with host cell surface releasing rest of viral genome

33
Q

non virulent

A

what most viruses are when they first enter a cell
dont causes disease

34
Q

provirus

A

DNA injected into host cell

35
Q

first step of lysogenic pathway

A

DNA inserted into host cell and is replicated every time host cell divides

36
Q

why is mRNA not produced in lysogenic pathway

A

because of production of repressor protein that makes it impossible to translate rest of the viral genetic material

37
Q

lysogeny

A

period when virus doesnt infect the host and make it ill

38
Q

latent

A

state of non virulent virus in cell

39
Q

what happens if viruses take the lytic pathway

A

the viral genetic material is replicated independently of the host DNA straight after entering the cell

40
Q

how does lytic pathway effect host

A

lots of mature viruses made and host cell bursts damaged

41
Q

virulent

A

viruses that cause illness

42
Q

how does a virus in lysogenic enter lytic pathway

A

under certain conditions when host cell damaged amount of repressor protein decreased and viruses enter the lytic pathway and become virulent

43
Q

what type of virus has lytic and lysogenic pathways

A

DNA viruses

44
Q

lysis

A

when bacteria cell burst of lytic pathway

45
Q

lysosome

A

enzyme produced when viruses replicate in lytic pathway and induce bacteria cells bursting

46
Q

how to +ssRNA replicate

A

have sense strand that directly used as mRNA for translation into proteins at ribosomes

47
Q

what proteins are made when positive ssRNA replicate

A

structural proteins
RNA polymerase - replicates the viral RNA

48
Q

how is negative ssRNA transcribed

A

virus imports RNA replicase which used free bases in host cell to transcribe antisense strand and produces a sense strand thats translated at ribosomes

49
Q

what happens once RNA transcribed in -ssRNA

A

acts as mRNA at ribosomes and codes for viral proteins

50
Q

role of negative ssRNA proteins produced

A

combine with replicated viral RNA to form new viral particles

51
Q

how do retroviruses replicate

A

viral RNA transcribed into DNA by reverse trabscriptase in cytoplasm of cell
viral DNA passes out of nucleus and inserted in host DNA
host transcriptase enzymes make viral mRNA and new viral RNA genome
-new particles released via exocytosis

52
Q

why are viruses specific

A

because each cell has own markers and virus only bind to particular markers

53
Q

how do antiviral drugs work

A

-target enzymes that aid in translation
-inhibit protease enzymes that enable new particles to be produced
-target receptors that recognize target cells

54
Q
A

biology topic 2 (cells and viruses) (10 decks)

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