Question

The model that is now known to be correct for the structure of biological membrane is :

• A. Lock and Key model
• B. Page’s model
• C. Fluid mosaic model
• D. Lac Operon model

Answer 1

The correct option is C Fluid mosaic model

The currently accepted model for the structure of the plasma membrane, called the fluid mosaic model, was first proposed in 1972 by Singer and Nicolson.

The fluid mosaic model describes the plasma membrane structure as a mosaic of phospholipids, cholesterol, proteins, and carbohydrates. The “mosaic” term of this model refers to the mixture of lipids and intrinsic proteins in the membrane. These boundaries are also “fluid” because their components can move laterally, allowing both diffusion of components and local specific gatherings.

A fluid mosaic model is presented for the gross organization and structure of the proteins and lipids of biological membranes. It consists of phospholipid bilayer in which proteins are embedded.

The movement of a molecule from one surface of the biological membrane to the other is called the flip-flop movement or transverse diffusion. This movement helps the cell membrane maintain its role as a barrier between the inside and outside of the cell environments.