Question

Inindicate which of the following lipids are polar and which are non-polar? 1. Ergosterol 2. Phosphatidylethanolamine 3. Arachidonic acid 4. Coenzyme Q8 5. Rhamnolipid

Answer 1

1:ERGOSTEROL:Ergosterol is a sterol found in cell membrane of fungi and protozoa. Sterols are a subgroup of steroids with a hydroxyl group on the A-ring is POLAR.The rest is aliphatic chain is non-polar.

2:PHOSPHATIDYLETHANOLAMINE:It is a POLAR head group, which creates a more viscous lipid membrane.This is found in all living cells, composing 25% of all phospholipids.

3:ARACHIDONIC ACID:Arachidonic acid is highly NON-POLAR.But by definition and technically-amphipatic.The carboxylic group at the end of carbon chain is hydrophilic region, but is rather small compound to the 20-carbon chain(hydrophobic).

4:COENZYME Q8:The long hydrocarbon chain gives the NON-POLAR property to the molecule. CoQ acts as a bridge between enzyme.

5:RHAMNOLIPID:There are Polar hydrophilic and Non-polar hydrophobic group in rhamnolipid molecule which always exhibits high surface or interfacial activity.