Week 3 Diebel Review

Question 1

How does bacterial staining differentiate between Gram + and - ?

Answer 1

Gram + –> purple, thick peptidiglycan cell wall

Gram - –> pink, thin peptidoglycan layer between inner and outer membrane

Question 2

What are the virulence factors of Salmonella?

Answer 2

O antigen–inhinits phagocyte killing

anti-phagocyte protein induced by ocyR

LPS–endotoxin, produces fever

Injectosome–help hide?

Enterotoxin–diarrhea

Type 1 fimbriae–adherence

Cytotoxin–inhibits host cell protein synthesis

Vi Capsule antigen- inhibits complement binding

Flagellum–motility

H antigen–adherence

Question 3

Contrast lytic and lysogenic bacteriophages.

Answer 3

lytic destroys host cell

lysogenic/temperate does not

Question 4

What structures are common among all viruses?

Answer 4

genetic material and capsid

Question 5

genetic info and replication for Class 1?

Answer 5

dsDNA (+/-), semiconservative replication of minus strand

Question 6

genetic info and replication for Class 2?

Answer 6

ssDNA (+), synthesis of dsDNA intermediate, semiconservative, discards (-) strand

Question 7

genetic info and replication for Class 7?

Answer 7

dsDNA (+/-), transcription followed by reverse transcription

Question 8

genetic info and replication for Class 3?

Answer 8

dsRNA (+/-), makes ssRNA (+) and transcribe from this to give ssRNA (-) partner

Question 9

genetic info and replication for Class 4?

Answer 9

ssRNA (+), makes ssRNA (-) and transcribe from this to give ssRNA (+) partner

Question 10

genetic info and replication for Class 5?

Answer 10

ssRNA (-), makes ssRNA (+) and transcribe from this to give ssRNA (-)

Question 11

genetic info and replication for Class 6?

Answer 11

ssRNA (+), makes ssRNA (+) by transcription of (-) strand of dsDNA

Question 12

What are the differences between the innate and adaptive immune systems?

Answer 12

Innate is ready to go all the time
-macrophages and dendritic cells

Adaptive must be “trained” in lymphocytes

• T cells and B cells
• has memory
• quicker and stronger response to reexposure

Question 13

What type of cells are first response in tissue?

Answer 13

macrophages and dendritic cells

Question 14

what is opsonization?

Answer 14

the antibody marks a pathogen for destruction by a phagocyte

Question 15

what are the methods for bacterial genetic exchange?

Answer 15

Homologous recombination-cross strand exchange from one chromosome to another
Transformation-free DNA is picked up by a competent host cell
Transduction (generalized and specialized)-transfer of DNA from one cell to another via bacteriophage
Conjugation-requires cell to cell contact transfer through a pilus
Transposition-discrete segments of DNA move as a unit from one location to another within in other DNA moleculs

Question 16

What is the virulence factor that HCV uses to shut off intracellular innate immunity? how does it work?

Answer 16

NS3/4A, blocks TRIF and MAVS of host cell which are in charge of creating IFN-B

Question 17

What are selective and differential medias and how do they function in general?

Answer 17

Selective: contains compounds that selectively inhibits growth of some microbes but not others

Differential: contains an indicator, usually a dye, that detects particular chemical reactions occurring during growth