Question

Mark the component which is not the part of lipid bilayer?

(a) Glycerol or Sphingosine

(b) Fatty acids

(c) Tryptophan and methionine

(d) Phosphate

The question was posed to me during an internship interview.

Origin of the question is Structure of Eukaryotic Cell topic in section Cell Structure and Functions of Life Sciences

Answer 1

Right choice is (c) Tryptophan and methionine

The explanation is: Phospholipids are composed of two types of components one is hydrophobic and other is hydrophilic. The fatty acid component is only hydrophobic while rest of the molecules is hydrophilic i.e. glycerol, phosphate, and alcohol attached to phosphate.