chapter 5: viruses and prions

Question 1

what is a virus?

Answer 1

an infection agent with a capsid ( a capsid is a protien coating)

Question 2

does a virus have an independent metabolism?

Answer 2

no

Question 3

when does the virus multiply?

Answer 3

once it is inside the host cell

Question 4

can viruses synthesize proteins?

Answer 4

no

Question 5

what does it mean for a virus to be filtrable?

Answer 5

that when a virus filters through a fluid, the fluid is still infectious

Question 6

what is a bacteriophage?

Answer 6

a virus that infects bacteria

Question 7

what are the 2 parts to a virus?

Answer 7

a capsid (a protein covering) and a nucleic acid

Question 8

what is an envelope?

Answer 8

the outside layer to the virus

Question 9

what is a naked virus?

Answer 9

a virus without an envelope

Question 10

why do viruses have spikes on the outside?

Answer 10

to aid it in the attachment of the host

Question 11

what is the capsid composed of?

Answer 11

capsomeres

Question 12

what is the helical shape of a capsid?

Answer 12

when it is in a helix shape, resembling DNA or RNA

Question 13

what is an icosahedral virus?

Answer 13

a shape with 20 faces

Question 14

what is a complex capsid?

Answer 14

an elaborate structure in bacteriophages

Question 15

how do viruses attach to the host cell?

Answer 15

through the spikes that attach to the host cell

Question 16

can viruses infect multiple hosts?

Answer 16

yes

Question 17

what does the virus do once it enters the host cell?

Answer 17

it makes copies of its material

Question 18

can some viral infections cause cell death?

Answer 18

yes

Question 19

what happens when a virus does not kill the host?

Answer 19

it stays in the cell, replicating and then it remains dormant until later

Question 20

what does it mean for a phage to be virulent?

Answer 20

it multiplies immediately

Question 21

what does temperant mean?

Answer 21

that the virus remains dormant until needed

Question 22

what is lysogenic conversion?

Answer 22

the temperate symptoms don’t exhibit until the toxin is activated

Question 23

what are prions?

Answer 23

infectious particles with no nucleic acid