Immuno - Microbial Infection Flashcards
What are viruses?
Not cells in their own right - obligate parasites
What do viruses contain as their genetic material?
DNA or RNA
How do viruses replicate?
Using cells nuclear replication machinery
What type of specificity do viruses exhibit?
Show some host cell specificity however they infect almost all other forms of life.
How do viruses divide from one another?
Budding from host cells, sometimes allowing the virus to have an outer membrane.
Or cytolysis where a host cell ruptures, therefore releasing virus into the environment.
What are the routes of viral infection?
Faecal oral
Blood borne
Air borne
Insect vectors
What is an example of a virus, its genetic material and its ability to replicate and divide?
HIV is an enveloped virus that contains RNA and there reverse transcriptase. HIV allows the host cell to survive after budding.
What are bacteria?
Prokaryotes
What do bacteria lack in terms of cell structure?
No organelles or internal membranes
What bacteria have internal membranes?
Photosynthetic bacteria (not pathogenic)
Are prokaryotes haploid or diploid?
Haploid
What does the haploid number of chromosomes in a bacteria mean in terms of effect?
Mutated genes in bacteria will always have an effect.
What makes up the cell wall of bacteria?
Peptidogylcan
How do bacteria divide?
Binary fission - very rapidly cells can reach rapid numbers due to exponential division
What is the role of the pilli?
Important for cell adhesion
What is the role of capsule?
Prevent cells desiccation and hinder phagocytosis
What is the role of the flagella?
Aid in motility of the cell
How is the shigella bacteria transmitted and were does it affect?
Faecal oral route - affects the GI tract.
Why does the shigella bacteria have no flagella?
Cells has developed a mechanism so that it can nucleate host cell actin filaments at the tail of the bacteria. This then allows the bacteria to be propelled around the cytoplasm and thus infect other cells