Final: Chapter 6- Viruses

Question 1

What is a viral capsid?

Answer 1

Shells around the virus that protects the DNA/RNA inside.

Question 2

What is the difference between a “naked virus” and an enveloped virus?

Answer 2

Enveloped viruses have an external layer around their capsid. Naked viruses do not have an envelope

Question 3

How do enveloped viruses acquire their envelope?

Answer 3

Capsid are spontaneously assembled during the formation of a virus, inside of host cells. This occurs due to the fact that most capsids consist of identical repeating subunits called capsomers.

Question 4

What are the 6 phases of the viral life cycle?

Answer 4

1) absorption
2) penetration
3) uncoating
4) synthesis
5) assembly
6) release

Question 5

How are absorption and viral host range directly related?

Answer 5

In order for the virus to successfully absorb to the host cell’s glycoprotein receptors there must be a match between the receptor and the spikes located on the viral capsid. (Host range of a virus is a term that describes what types of organisms a virus can infect)

Question 6

What are the 2 mechanisms by which mature viruses can be released from host cells?

Answer 6

1) exocytosis

2) lysis of the host cell

Question 7

What are cytopathic effects?

Answer 7

Any viral-induced damage to cells that alters their microscopic appearance. (Disorientation, change in cell shape, change in size, intracellular changes)

Question 8

What are oncongenic viruses?

Answer 8

Viruses that enter their host cell and permanently alter its genetic material leading to cancer.

Question 9

What are bacteriophages?

Answer 9

Viruses that infect bacteria

Question 10

What are prions and what effect do they have on the brains of infected animals?

Answer 10

Infectious proteins transmittable through certain bodily fluids. They are thought to lead to protein disposition in the brain and nervous tissue leading to slow degeneration of cells.