3a starting at respiratory burst

Question 1

Where does respiratory burst occur and why?

Answer 1

Occurs in phagocytes(Neutrophils that are highly specialzed for the uptake and killing of pathogens and containing cytoplasmic granules

Question 2

What is respiratory burst?

Answer 2

When cells take in a lot of oxygen in short amount of time

Question 3

primary (azurophilic) granules:

Answer 3

contain antimicrobial peptides and enzymes

Question 4

secondary (specific) granules

Answer 4

formation of toxic oxygen species

Question 5

What is the role of NADPH and how is it formed? Role oxidase in the production of ROS?

Answer 5

NADPH is formed (formed by fusion of phagosome with lysosomes and primary and secondary granules)

When active, it can transfer electrons from NADPH to O2- molecules to produce the superoxide ion(O2-). This is can be converted to other free oxygen radicals (ROS).

Question 6

What is ROS, its components, and the role in the killing of pathogens?-

Answer 6

hydrogen peroxide (H2O2) by superoxide dismutase (SOD)

hypochlorite (OCl–) by myeloperoxidase, a heme-containing enzyme

hydroxyl radical (*OH) by chemical reaction with ferrous (Fe2+) ions (
They are termed collectively reactive oxygen species (ROS)

• Toxic because they are free. Can only kill whatever is inside(the bacteria)
  Can be converted into the O2- ion.

Question 7

What does acidification dissociate using what? What can it also cause?

Answer 7

important-dissociates granule enzymes such as cathepsin G and elastase from their proteoglycan matrix

Can also cause cleavage and activation of granule enzymes by lysosomal proteases

Question 8

In resting neutrophils, cytochrome b558 subunits (gp91 and p22) of NADPH oxidase are
localized in______-other oxidase components (p40, p47, and p67) are
located in _____

Answer 8

plasma membrane
cytosol

Question 9

What activates Rac and induces the assembly o the complete, active NADPH s
synergizes to activate Rac and induce the assembly of the complete, active NADPH oxidase
in membrane of phagolysosome (formed by fusion of phagosome with lysosomes and
primary and secondary granules)?

Answer 9

phagocytic receptors and by fMLF or C5a receptors

Question 10

Active NADPH oxidase transfers electrons to O2 molecules. This produces what? And then gets converted to

Answer 10

Produces super oxide ionO2- and gets converted to other free oxygen radicals termed ROS

Question 11

Which ions are drawn into phagolysosome to neutralize charged o2- to increase acidification? What does acidification do?

Answer 11

Potassium and hydrogen ions

Acidification- dissociated granule enzymes such as cathespin and elastase which also leads to cleavage and activation of granule enzymes by lysosomal proteases