Eicosanoids

Question 0

Eicosanoids are derivatives of … C fatty acids

Answer 0

20

Question 1

What is meant by polyunsaturated fatty acids?

Answer 1

More than one double bond

Question 2

Docosanoids are derivatives of … C fatty acids

Answer 2

22

Question 3

What is a healthy ratio of linoleic acid to a-linoleic acid (Omega 6/3)?

Answer 3

4:1

Question 4

Eicosanoids act as what?

Answer 4

Local signaling molecules

Question 5

What are the 4 major categories of Eicosanoids?

Answer 5

Prostaglandins (PG), Prostacyclins, Leukotrienes (LT), Thromboxanes (TX)

Question 6

Where are PGs formed?

Answer 6

Many tissues

Question 7

Where are Prostacyclins produced?

Answer 7

Endothelium

Question 8

Where are Leukotrienes produced?

Answer 8

Immune system cells

Question 9

Where are Thromboxanes produced?

Answer 9

Platelets

Question 10

What structure is the basis for all PGs?

Answer 10

Prostanoic acid

Question 11

Which bonds projecting from the rings are in a trans position?

Answer 11

8-12

Question 12

All PGs have a hydroxyl at which carbon?

Answer 12

C-15

Question 13

What is the order of double bonds for PGs designation?

Answer 13

13-14, 5-6, 17-18

Question 14

Leukotrienes are …. structures containing … bonds

Answer 14

Open-chain; 3-5 double bonds

Question 15

What are all leukotrienes derivative of?

Answer 15

HPETEs

Question 16

What does the numerical subscript indicate in the naming of leukotrienes?

Answer 16

The number of double bonds

Question 17

Is arachidonic acid an omega 3?

Answer 17

No, it is an omega 6

Question 18

How many double bonds in arachidonic acid? Where are they?

Answer 18

20:4 delta 5, 8, 11, 14

Question 19

Arachidonic acid is central to the synthesis of which lipids?

Answer 19

Prostaglandins, thromboxanes, and leukotrienes

Question 20

Where are aa and other precursors for eicosanoids stored in the cells?

Answer 20

C2 position of membrane pospholipids

Question 21

What enzyme releases aa from storage?

Answer 21

Phospholipase a2

Question 22

Linoleic acid is the parent of which fatty acid family?

Answer 22

Omega 6

Question 23

a-linolenic acid is the parent of which fatty acid family?

Answer 23

Omega 3

Question 24

What is the delta designation of linoleic acid?

Answer 24

18:2^9,12

Question 25

What is the delta designation of a-linolenic acid?

Answer 25

18:3^9,12,15

Question 26

The physiological effects of the various eicosanoids may be manipulated by changing what?

Answer 26

Fatty acid composition of the diet.

Question 27

Thromboxanes are similar to PG except that...

Answer 27

The ring is 6-membered, oxy-heterocyclic

Question 28

What is the definition of a leukotrienes?

Answer 28

Open-chain structures containing 3-5 double bonds

Question 29

What class of enzymes initiate conversion of arachidonate and other precursors into PG's and TX's?

Answer 29

Cyclooxygenases (COX)

Question 30

What do cyclooxygenases initiate?

Answer 30

Conversion of arachidonate and other precursors into PGs, TXs

Question 31

What class of enzymes convert arachidonate into HPETEs (precursor for LTs) or into lipoxins?

Answer 31

Lipoxygenases (LOX)

Question 32

Lipoxygenases (LOX) convert what?

Answer 32

Arachidonate into HPETEs, (precursor for LT), or into lipoxins

Question 33

Which pathway is referred to as the cyclic pathway?

Answer 33

COX

Question 34

Which pathway is referred to as the linear pathway?

Answer 34

LOX

Question 35

When are eicosanoids inactivated?

Answer 35

When the hydroxyl at C15 is oxidized to a ketone.

Question 36

How to steroids act as an anti-inflammatory?

Answer 36

Induce synthesis of lipocortin, which inhibits phospholipase A2

Question 37

How do NSAIDs work?

Answer 37

Inhibit COX

Question 38

Is aspirin reversible or irreversible?

Answer 38

Irreversible

Question 39

Is ibuprofen reversible or irreversible?

Answer 39

Reversible

Question 40

What do steroids and NSAIDs modulate?

Answer 40

Modifying aa release

Question 41

The capacity for arachidonic acid synthesis is greater with which diet addition?

Answer 41

G-linolenic acid (GLA)