Viruses

Question 1

what is a virus

Answer 1

very small infectious obligate intracellular parasite

Question 2

what is a progeny viron

Answer 2

fromed in host cell

Question 3

what does a progeny viron do?

Answer 3

means of transmitting of virus to next host cell

Question 4

what are a viruses properties of life

Answer 4

1. cellular respiration
2. reproduction
3. metabolism
4. hereditory
5. responcivness
6. growth and development

Question 5

what does a host provide for a virus to reproduce and spread to a new host

Answer 5

> nucleotides for nucelic acids
ribosomes and amino acids for translation of proteins
ATP for enegry
Golgi and ER for protein processing

Question 6

what are nucleotides useful for

Answer 6

nucleic acids

Question 7

what are ribosomes and amino acids useful for

Answer 7

translation of proteins

Question 8

what is ATP useful for

Answer 8

energy

Question 9

what is the golgi and ER useful for

Answer 9

protein processing

Question 10

how are viruses categorised (topic and subtopic)

Answer 10

nucelic acid– DNA/RNA
capsid symmetry – helical, icosahedral, complex
presence/absence of envelope– naked/enveloped
genome charictoristics

Question 11

what makes a virus

Answer 11

nucleic acid (DNA/RNA)
protein  coat (CAPSID) surrounding nucleic acid
sometimes envelope sometime a capsule

Question 12

describe bacteriophage

Answer 12

infect and replicate within bacteria
highley virulent for bacteria
complex structure
classified by shape and nucleic acid

Question 13

what is bacteriophage structure

Answer 13

head, collar, tail, tailspins, tail fibres

Question 14

what is bacteriophage life cycle

Answer 14

1. attachment
2. penetration/entry (injection)
3. Synthesis of nucleic acid and protein
4. assembly and packaging
5. release (lysis)

Question 15

describe attachment

Answer 15

> all viruses have attachment proteins on outside
protein attaches to specific receptors on host cell surface
receptors are normal proteins found on outside of the host cell

Question 16

what is lambada an example of

Answer 16

bacteriphage

Question 17

describe lambada

Answer 17

bacteriophage, temperate, has 2 life cycles

enters either the lytic pathway or lysogenic pathway depending on series of complicated genetic events

Question 18

describe lytic cycle

Answer 18

infected bacteria are production factory for lambada and are lysed to release new bacteriophage

Question 19

describe lysogenic cycle

Answer 19

bacteriophage genome is incorporated into bacterial host chromosome by genetic recombination that occurs at specific sites on chromosome

Question 20

what is prophage

Answer 20

name for bacteriophage DNA when inserted in bacterial host chromosome

Question 21

name a plant virus

Answer 21

tabacco mosaic virus

Question 22

describe tobacco mosaic virus

Answer 22

helical symmetry, 2130 identical capsomers
helical nucleocapsid
Viral DNA

Question 23

where is envelope on virus derived from

Answer 23

cell, golgi or nuclear membrane

Question 24

example of enveloped virus

Answer 24

measles/ influenza

Question 25

describe plaque assay

Answer 25

virus innoculated on monolayer of cells/ bacteria overlay of agar added virus can only spread from cell to cell holes or plaques of dead cells in monolayer modifications are used if virus does not form plaques

Question 26

what is a plaque layer used for

Answer 26

isolate single virus

Question 27

name effects of virus infection on cell

Answer 27

1. lysis- cell death 2. transformation - tumor formation 3. cytopathic effect- under microscope 4. persistent infection of cell 5. latent infection of cell (can become lytic)

Question 28

describe virus glycoproteins

Answer 28

matrix protein links virus nucleocapsid to membrane. | form spikes on outside of virus

Question 29

what are glycoproteins the main antigens for

Answer 29

immune systems

Question 30

describe enveloped virus cell cycle

Answer 30

envelope fuses with cell membrane, synthesis of nucleic acid genome and viral proteins ER of cell makes viral glycoproteins progency viruses bud from cell cell membrane remains intact doesn't kill host

Question 31

what is an envelope

Answer 31

lipid bilayer with glycoprotein spikes

Question 32

describe human immunodeficiency virus

Answer 32

single stranded enveloped retrovirus (RNA) has virus latency

Question 33

describe primary cell culture

Answer 33

obtained from live animal tissue -- limited life

Question 34

what is the life of a primary cell culture

Answer 34

limited

Question 35

describe diploid cell lines

Answer 35

homogenous cells from embryo | divide around 100x then die

Question 36

where do diploid cell lines come from

Answer 36

embryo

Question 37

describe continuous cell lines?

Answer 37

imortal cell lines (never stops growing) | usually from cancerous cell

Question 38

where do continuous cell lines usually come from

Answer 38

cancerous cell

Question 39

what is virus latency

Answer 39

allows virus to avoid detection by immune system