Question

Who gave the biomolecular leaflet model?
A. Robertson
B. Singer and Nicholson
C. Wolpers
D. Danielli and Davson

Answer 1

Hint: A plasma membrane model in which the protein layer flanked a central phospholipid layer and proteins coat the outer surface.

Complete answer: In 1935 Hugh Davson and James Danielli proposed a model for plasma membrane known as a sandwich or unimolecular model.
1. This model describes that a phospholipid layer lies between two protein layers.
2. This was the first model that describes the position of lipids and proteins in the cell membrane.
3. The lipid layer was coated by the hydrated proteins.
4. In this type of arrangement, proteins and phospholipid leaflets are associated with electrostatic interaction formed between the polypeptide of amino acids and the polar ends of lipids.
5. Other groups are attached to the outer surface of proteins through electrostatic or Vander Waal force.

Hence, the correct option is (D) Danielli and Davson.

Note: Danielli and Davson proposed the ‘lipid-protein sandwich’ model in which the membrane shows selective permeability, that allows selective molecules to pass through the membrane. The lipid bilayer is made up of phospholipids have hydrophilic heads and hydrophobic tails.