Ch. 4 Virology

Question 1

major functions of virion proteins

Answer 1

protection, delivery, vesicular transport, immune evasion proteins, cellular transcription factors

Question 2

Name for viral membrane

Answer 2

envelope

Question 3

minimal size of object visible on electron microscope

Answer 3

50-75 angstrom

Question 4

Minimal size of object visible in Cryoelectron microscopes is

Answer 4

6 angstrom (alpha-helix)

Question 5

Two types of viral capsid symmetry

Answer 5

1: helical symmetry
2: Icosahedral symmetry

Question 6

The icosahedron has __ faces, __ vertices, ___ triangles interact at each vertice

Answer 6

20; 12; 5

Question 7

The size of the icosahedron is determined by the size of the

Answer 7

protein subunit

Question 8

A triangular face of an icosahedron is made up:

Answer 8

triangular facets

Question 9

simple triangular faces are composed of a _____ of protein subunits

Answer 9

trimer

Question 10

the 3 Packaging the genome methods:

Answer 10

1: direct contact, capsid is + charged (nonspecific binding)
2: specialized viral proteins provide energy from ATP, nucleocapsid proteins bind to packaging signal in RNA
3: Cellular proteins package genome (genome is organized into centrosomes

Question 11

Components of viral envelope

Answer 11

Derived from cellular membranes

glycoproteins- oligosaccharides covalently bonded to proteins

Question 12

Glycoproteins

Answer 12

1: Virus receptors
2: Major antigenic determinants
3: mediate fusion of viral and cellular membranes during entry

Question 13

Hemagluttinin protein of human influenza is a trimer of disulfide linked HA1 and HA2 molecules

Answer 13

True