Elongation/ Desaturation And Essential Fatty Acids

Question 0

N-3 fatty acids

Answer 0

• they can be oxidised and used as fuel
• enriched in the phospholipids fraction of membranes
• substrates for ecosanoids which have different activities compared to those derived from the n-6 fatty acids
• specific in vision, CNS and sperm

The long chain n-3 fatty acids (C20:5 and C22:6) are biologically very active and have special functions:
C20:5= eicosapentaenoic acid (EPA)- a precursor for ecosanoids- the ecosanoids products generally have a beneficial effects on blood clotting and inflammation and so high dietary uptake of n-3C20:5 is assosiated with reduced inflammatory response or lower rate of cardiovascular disease.
-C22:6 = Docosahexaenoic acid (DHA)- this fatty acid is enriched into the myelin sheaf and is assosiated with nerve/brain function and vision.

Question 1

N-6 fatty acids

Answer 1

• they can be oxidised and used as a fuel
• enriched in the phospholipids fraction of membranes
• substrates for ecosanoids which have different activities compared to those derived from the n-3 fatty acids.
• help emulsify fats and form micelles in the small intestine aiding in digestion.
• involved in reducing surface tension in the lung alveoli

Question 2

Check out the pathways for fatty acid elongation

Answer 2

Pg 54

Question 3

What does thromboxane and proteoglycans do?

Answer 3

Thromboxane ➡ pro aggrecan

Proteoglycans➡ anticoagulants

Question 4

What is the parent fatty acid of n-6

Or n-3?

Answer 4

N-6: linoleic acid C18:2
N-3: linolenic acid C18: 3
You can then make the rest once you have these by elongation and desaturation