Question

According to the unit membrane concept (Robertson model), the plasma membrane has the following arrangement:

• A. Protein and lipid layers intermingled
• B. Protein-lipid-protein
• C. Lipid-protein-lipid
• D. Protein-lipid-lipid

Answer 1

The correct option is B

Protein-lipid-protein

The correct option is B:

Explanation of the correct option:

1. The unit membrane model was given by Robertson in the year 1959.
2. According to his thesis, all the cellular membranes are structurally and functionally similar.
3. He proposed that the cellular and the organellar membrane is a lipid bilayer enclosed by protein on either side.
4. It was rejected because he failed to explain the concept of selective permeability.
5. The correct arrangement according to the unit membrane model is protein-lipid-protein.

Final answer: According to the unit membrane concept (Robertson model), the plasma membrane has the protein-lipid-protein arrangement.