Infectious Agents Flashcards
0
Q
When is gram staining purple?
A
Positive
1
Q
Distinguish between necessary, sufficient and specific
A
Necessary - disease cannot occur in the absence of the cause
Sufficient - cause alone can lead to the disease
Specific - cause is absent in other diseases
2
Q
When is gram stain red?
A
Negative
3
Q
Describe structure and function of capsids
A
Composed of capsomeres. Protects delicate inner nucleic acid - can be shaped as an icosahedral or helical
4
Q
How do viruses work?
A
Absorbed into host cells by first binding to receptors on host cell. Mediated endocytosis or crossing the host cell membrane via coated pits or fusion
5
Q
How are viruses diagnosed?
A
Through culturing in cell culutres
6
Q
How are viruses characterised?
A
By incubation period; virus replicates within the host
