Virus Structure and Classification

Question 1

What is a virus?

Answer 1

• obligate intracellular parasites - they are associated with all formas of life - defined as: a caspid-encoding organism

Question 2

What is a caspid?

Answer 2

protein shell that encapsulates the nucleic acid genome structural

Question 3

What is a virion?

Answer 3

the particle encoded by a virus genome

Question 4

What is avirus genome made up of?

Answer 4

1. caspid protein gen 2. replicon= encodes polymerase and accessory proteins 3. genes for multifunctional proteins that interact with the host (non structural so left behind in host)

Question 5

Caspid structures

Answer 5

Helical (spiral) Icosahedral complex

Question 6

Virion structure

Answer 6

genome + caspid +/- envelope naked = no envelope envelope comes from the host lipid bilayer

Question 7

Virus classification

Answer 7

Host Cell Kingdom (Euk v. Pro, Plant, insect, animal) Genome type ( RNA v DNA, Single or double) Virion Structure (Envelope v. naked, Helical v. icosahedral v. complex)

Question 8

Virion components: Genome Segments Nucleocaspid Caspid or core Tegument Matrix Envelope Glycoprotein Spike or fiber

Answer 8

Genome Segments Nucleocaspid = viral caspid protein + genome Caspid or core Tegument = gel of proteins Matrix = protein layer linking the viral envelope to the caspid Envelope = outer lipid layer Glycoprotein = docked in lipid layer Spike or fiber = glycoprotein

Question 9

Structure of :

1. Adenovirus
2. Poxvirus
3. Influenza virus
4. Retrovirus (HIV)
5. Herpesvirus

Answer 9

1. icosahedral, dsDNA, Naked
2. Complex, dsDNA, Enveloped
3. Helical, Segmented RNA, Enveloped
4. Icosahedral, ssRNA, Enveloped
5. Icosahedral, dsDNA, Enveloped