Question

5. A common structural feature of membrane lipids is their amphipathic nature. For example, in phosphatidylcholine, the two fatty acid chains are hydrophobic and the phosphocholine head group is hydrophilic. For each of the following membrane lipids, name the components that serve as the hydrophobic and hydrophilic units. (5 pts)

   a) phosphatidylethanolamine

   b) sphingomyelin

   c) galactosylcerebroside

   d) ganglioside

   e) cholesterol

Answer 1

a) Phosphatidylethanolamine

Two fattyacid chains are hydrophobic and phosphoethanolamine head is hydrophilic in nature.

b) Sphingomyelin

Sphingosine and fatty acid chain are hydrophobic in nature and  phosphocholine or phosphoethanolamine head is hydrophilic in nature.

c) Galactocerebroside

Ceramide is hydrophobic in nature and Galactose is hydrophilic in nature.

d) Ganglioside

Ceramide is hydrophobic in nature and oligosaccharide is hydrophilic in nature.

e) Cholesterol

The whole ring structure is hydrophobic in nature and hydroxyl group attached to it is hydrophilic in nature.