WBCs metabolism

Question 1

illustrate the acute inflammatory response

Answer 1

1. inc vascular permeability
2. entry of the activated neutrophil into the tissue
3. activation of platelet
4. spontaneous subsidence (resolution) if the invading microorganisms have been dealt with
5. one of the mechanisms of dealing with microorganisms is production of reactive oxygen species (ROS)

Question 2

the electronic structure of oxygen favors its …….. by addition of one electron at a time leading to generation of …….

Answer 2

reduction
ROS

Question 3

…………produced during the metabolism.

Answer 3

powerful oxidants

Question 4

……… is a large family which is not always a free radical

Answer 4

ROS

Question 5

………….lack superscript dot of free radical.

Answer 5

hydrogen peroxide

Question 6

why hydrogen peroxide considered as ROS?

Answer 6

because its high reactivity

Question 7

def the free radical.

Answer 7

atoms or groups of atoms that have an unpaired electron

Question 8

list reactions involved in (ROS)

Answer 8

1. reaction (1) (superoxide):
   - in RBCs from auto-oxidation of Hb to Met-Hb. 3% daily
   - in other tissues by cytochrome P450 & xanthine oxidase
2. reaction (2) ( respiratory burst )
3. reaction (3) ( dismutase) :
   -spontaneous or by superoxide dismutase
4. reaction (4) (catalase)
5. reaction(5) ( myeloperoxidase):
   - myeloperoxidase which catalyezes the production of chlorinated oxidants
   - H2O2 and halides produce hypochlorus acid
6. reaction(6) :
   - glutathione peroxidase ( need selenium )
   - need reduced glutathione
   - can also use other peroxides as a substrate
7. reaction (7) : (the Fenton reaction)
   - non enzymatic reactions catalyzed by Fe+2 produce OH- & OH*
8. reaction (8) ( Haber Weiss reaction )

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Question 9

def of antioxidants

Answer 9

compounds and reactions disposing of these toxic oxidant species , scavenging them , suppressing their formation or opposing their actions

Question 10

list enzyme antioxidants

Answer 10

1. superoxide dismutase (SOD)
2. catalase
3. glutathione peroxidase

Question 11

list non enzymes antioxidants

Answer 11

NADPH , GSH , ascorbic acid (vit C) & vit E

Question 12

what’s oxidative stress ?

Answer 12

-imbalance between production of toxic Oxygen species ( pro-oxidant ) & activity of different anti-oxidants
- inc ROS by chemicals or drugs
- can result in serious cell damage if the stress is massive or prolonged.