Viral Infection Flashcards
1
Q
What are viruses?
A
- Infectious, obligate intracellular parasites containing genetic material
- Often surrounded by protein coat
2
Q
What are the inner components of a virus?
A
- Viral genome - either DNA or RNA
- Viral enzymes - required for viral replication within host cell e.g reverse transcriptase
3
Q
What are the outer components of a virus?
A
- Capsid - single or double layer protein shell surrounding nuceloid. Made up of capsomers
- ENVELOPE - Surrounds capsid. Made up of virus-specific proteins, lipids and carbohydrates
3
Q
What are susceptible and resistant cells?
A
- SUSCEPTIBLE - receptor for virus. May or may not support viral replication
- RESISTANT - similar to susceptible but no receptor
4
Q
What are permissive cells?
A
- Capacity to replicate virus - may or may not be susceptible
- A cell that is permissive and susceptible is the only cell that is able to take up a viral particle and replicate
5
Q
Describe the viral life cycle.
A
- INOCULATION - viral inoculum binds to cells
- ECLIPSE - virions penetrate cells
- BURST - host cells release viral particles
- BURST SIZE - number of virions released per infected cell
6
Q
How can sialic acid receptors cause zoonotic spillover?
A
- Extensively distributed across various animal hosts
- Facilitate emergence of multiple viruses
- Zoonotic spillover - leading to epidemics
7
Q
What enzyme catalyses formation of +ssRNA from -ssRNA?
A
Viral RNA-dependent RNA polymerase
8
Q
What is the purpose of the capsids?
A
- Protect nucleic acids
- Facilitates viral entry into host cells
9
Q
What are cytokine storms?
A
- Sudden release of cytokines e.g TNF, interleukin 1, interferon α
- In response to infections (usually respiratory) e.g COVID-19
10
Q
What are bacteriophages?
A
- Viruses that infect bacteria
- Contain proteins that will encapsulate the DNA/RNA genome
