Question

What is the significance of where double bonds are on fatty acids… and why it is different between humans and bacteria

Answer 1

Ans:- Significance of double bonds on fatty acids:- fatty acids containig double bonds are called as unsaturated fatty acids, their classification depends on the position of the double bonds first double bonds from the end of the chain, presence of double bonds on fatty acids produces a kink in the molecule this is because the double bond cannot rotate.

1) The incorporation of phospholipids in the plasma membrane for eg, n-6 or n-3 polyunsaturated fatty acids often affect the regulatory physiology upon appropriate stimulus, the fatty acid is freed and then converted into a regulatory molecule or paracrine that act locally in nearby cells .

2) When a fatty acid is unsaturated and has a short chain length, it increases the fluidity of the membrane .

3) they donot get stick to the walls of blood vessels and hence promote blood flow.

4) they are liquid at room temperature because of presence of the double bonds in them which produces a kink and hence a reason why they are liquid at room temperature.

5) they are associated with varoius health benefits.

6) at higher temp. some bonds rotate causing chain shortening which explains why biomembranes become thinner with increase in temperature.

7) Membrane fluidity is crucial to the proper functioning of membrane-associated structures: receptors, transporters, and the like. the fludity of membranes is possible because of presence of double bonds in fattyy acids.

Bacterial vs human unsaturated fatty acids:-

the unsaturated fatty acids are among the most important fatty acids from a biochemical standpoint and constitute a major portion of fatty acids in bacteria , the excessive unsaturated fatty acids in the baceria helps them to response to the environmental stimuli particularly where growth is inhibited due to presence of high concentrations of toxic substances bacteria convert the cis unsaturated fatty acids to trans unsaturated fatty acids changes the membrane fluidity hence they respond tot the external stimuli accordingly. C ¹⁸-Octadecenoic and palmitoleic acids are the major unsaturated acids in all the eubacteria.