Exam 1: lecture 3

Question 1

what is a virus

Answer 1

1)NOT alive
why?
not respire
cannot live on their own (need host)

2)have an RNA/DNA genome encased in special protective coat=capsid (glycoprotein/ lipoprotein)

3) cannot reproduce wo being inside a host cell

4) do not respond to antibiotics- antivirals

5) replication is dependent on taking over the genetic machinery of a cell and subverting it

6) species specific

=Molecular parasites

Question 2

How are viruses characterized?

Answer 2

-shape
-their host
-their genome
-size
-method of reproduction
-immunological characteristics
-flulike symptoms

Question 3

1 micrometer

Answer 3

1/ 1 millionth meters

Question 4

1 nanometer

Answer 4

1/1 billionth meter
10^-9

Question 5

basic viral structures: non-enveloped virus

Answer 5

dna
capsomeres (protein units)
capsid (protein coat)-protective genetic info
fiber: binding+ recognition

Question 6

basic viral structures: envelopedvirus

Answer 6

rna
capsid(protein coat)
envelope-made up of lipids+ proteins
spike : allow recognition

Question 7

bacteriophages

Answer 7

attack bacteria

Question 8

Lytic cycle

Answer 8

virus uses the host cells to reproduce

1. attachment: capsid combines with receptor
2. penetration: viral DNA enter host
   3: biosynthesis: viral components are synthesized
   4: maturation
3. new viruses leave host cell

Question 9

lysogenic cycle

Answer 9

virus dna is incorporated into the host genome and stays there until the lytic cycle is triggered
-this cycle happens bc there is not sufficient materials to reproduce

Question 10

prions

Answer 10

hyperstable protein- not a virus