Viral Infections

Question 1

What diameter do viruses range from?

Answer 1

20-450nm

Question 2

Viruses lack the machinery to do what?

Answer 2

Syntesise proteins

Question 3

What is a nucelocapsid?

Answer 3

Capsid is protein that surrounds nucleic acid.

Question 4

Describe the 6 step process of viral replication.

Answer 4

Absorption (virus attaches to cell). Penetration (virus engulfed into vesicle). Uncoating (envelope removed and RNA is cytoplasm). Synthesis (viral genes control cell to produce components for new viruses). Assembly (RNA and capsomers form nucleocapsid and viral spike proteins bind to cell membrane). Release (viruses bud off membrane).

Question 5

Difference between Endocytosis and Fusion as method of penetration.

Answer 5

Endocytosis: Whole virus enveloped.
Fusion: Just nucleocapid in.

Question 6

Describe course of viral infection.

Answer 6

Primary replication (after gaining entry into host the virus replicates). Systemic spread (virus may spread in blood stream or CNS) Secondary replication (replication at organs/tissues following spread).