P4 BIOCHEMISTRY

Question 1

a polyunsaturated omega-6 fatty acid containing 20 carbons

Answer 1

Arachidonic acid

Question 2

Arachidonic acid is derived from desaturation & elongation of

Answer 2

linoleic acid

Question 3

phospholipid that releases Arachidonic acid from membrane bound phospholipids

Answer 3

Phospholipase A2

Question 4

cox pathway occurs in

Answer 4

Endoplasmic reticulum

Question 5

Arachidonic acid is converted to prostaglandins by

Answer 5

oxidative cyclisation

Question 6

prostaglandins generated by mast cells

Answer 6

PGD2

Question 7

prostaglandins generated by macrophages

Answer 7

PGE2 & TXA2

Question 8

Isozymes of coxs

Answer 8

COX -1
COX- 2

Question 9

COX isozyme that is made in most tissues , promote or suppress leukotrienes synthesis

Answer 9

COX 1

Question 10

COX isoenzymes that is made in brain & kidneys & macrophages

Answer 10

COX 2

Question 11

COX 1 function

Answer 11

Maintenance of healthy gastric tissue
renal homeostasis
Platelets aggregation

Question 12

COX 2 function

Answer 12

mediates pain , heat , redness , swelling of inflammation
Fever of infection

Question 13

Thromboxane that is derived from prostaglandin H2

Answer 13

A type thromboxane / TXA2

Question 14

TXA2 is present in

Answer 14

ER , lungs , platelets

Question 15

TXA2 function

Answer 15

Stimulate platelets activation

Question 16

half life of TXA2

Answer 16

very short , 0.5 - 1 min

Question 17

inactive form of TXA2

Answer 17

Thromboxane B2

Question 18

site of synthesis of leukotrienes

Answer 18

Leukocytes , mast cells , macrophages

Question 19

lipoxygenase enzymes that converts Arachidonic acid to variety of hydroxyperoxyl acids

Answer 19

• 5-HPETE
  -12-HPETE
• 15-HPETE

Question 20

5-HPETE is major product of

Answer 20

Basophils , mast cells , macrophages , polymorphs

Question 21

12-HPETE is produced in

Answer 21

platelets,
pancreatic endocrine islets cells
glomerular cells of kidney

Question 22

12-HPETE is produced by what enzyme

Answer 22

12- lipooxygenase

Question 23

15-HPETE is produced by which enzyme

Answer 23

15-lipooxygense.

Question 24

15-HPETE is produced in

Answer 24

reticulocytes, eosinophils and T cells

Question 25

The 5-HPETE is converted to LTA4 through

Answer 25

5- lipoxygenase

Question 26

LTA4 is highly unstable, and it will serve as precursors for formation

Answer 26

LTB4, LTC4, LTD4 and LTE4

Question 27

LTA4 is converted predominantly to the chemoattractant LTB4 by

Answer 27

LTA4 hydrolase

Question 28

LTA4 is conjugated with reduced glutathione by what enzyme

Answer 28

LTC4 synthase

Question 29

LTA4 is conjugated with reduced glutathione by LTC4 synthase to form

Answer 29

leukotriene C4 (LTC4)

Question 30

conversion occurs to LTC4 to produce peptidoleukotrienes LTD4 and LTE4 by what enzyme

Answer 30

glutamyl transpeptidase & dipeptidase enzymes