Particles

Question 1

What is a capsid

Answer 1

Viral shell made of redundant protein subunits that protects the genome

Question 2

Blank + blank = virion

Answer 2

Genome + capsid

Question 3

Why form a virion?

Answer 3

Genome exposure is risky
(physical damage from mechanical shearing, chemical from UV, enzymatic from nucleases)

Question 4

What does a capsid do?

Answer 4

Protects the genome
Provides a surface for viral attachment proteins to bind host receptors
Hides genome from immune system until in right place

Question 5

Capsid formation

Answer 5

Must be small subunits or viral genome would be too large
Self assemble

Question 6

Virus Like Particles (VLPs)

Answer 6

No genome required, only one subunit gene
Ex- HPV vaccine

Question 7

Helical capsids

Answer 7

Irregular subunits form a helix
Allows flexibility and resistance to shear forces

Question 8

Most plant viruses are what type?

Answer 8

Helical and nonenveloped

Question 9

All helical animal viruses have what?

Answer 9

An outer lipid envelope

Question 10

How do capsids self assemble?

Answer 10

Electrostatic interactions (NAs are -, nucleocapsid/capsid is +, also N terminus is - and C terminus is +)
Hydrophobic interactions

Question 11

Nucleocapsid

Answer 11

Protects and provides structure

Question 12

Envelope

Answer 12

Stolen lipid membrane

Question 13

Matrix proteins

Answer 13

Connects nucleocapsid and envelope

Question 14

Envelope glycoproteins

Answer 14

Virus attachment proteins

Question 15

Icosahedral (isometric) capsids

Answer 15

Irregular identical subunits with several shape options (commonly dodecahedron (12 pentagons) or icosahedral (20 triangles))
More triangles equal more stable

Question 16

Naked viruses

Answer 16

Lyse cells when they exit

Question 17

All plant viruses are what?

Answer 17

Naked

Question 18

Pros of an enveloped virus

Answer 18

More efficient cell to cell transfer because envelope melts into host membrane
Doesn’t kill host cells

Question 19

Cons of an enveloped virus

Answer 19

Envelope is more prone to damage which reduces attachment
Slower replication
Cell still has viral episodes so cell still can be identified as infected

Question 20

Where is the budding assembly site?

Answer 20

The host plasma membrane normally (sometimes ER, golgi, or nuclear membranes)

Question 21

Maturation during budding

Answer 21

The rearrangement of capsid, genome, and matrix proteins to facilitate infection
Can occur before or after release from the cell

Question 22

Matrix proteins

Answer 22

Link nucleocapsid to the envelope

Question 23

Glycoproteins

Answer 23

Anchor in envelope and do multiple things such as adhesion, enzymatic functions, and ion channels