Question

″Proteins icebergs in a sea of lipids” is stated by

• A. Lamellar Model
• B. Unit-membrane Model
• C. Fluid-Mosaic model
• D. Micellar Model

Answer 1

The correct option is C Fluid-Mosaic model

In 1972, Singer and Nicholson proposed the Fluid Mosaic Model for plasmamembrane which is the most accepted model. They published their paper in the reputed journal Science in 1972. They described the plasmamembrane as protein icebergs in a sea of lipids. The model describes a central, continuous bilayer of lipid molecules that forms the structural framework of the plasmamembrane with their spherical, polar heads towards outer surface. The two non-polar tails of each molecule point inwards facing each other. In this way, the membrane forms a water resistant barrier, through which only lipid soluble substances can pass.The protein molecules are arranged in two different manners. Some pro­teins are located exclusively adjacent to the outer and inner surfaces of lipid bilayer and are called extrinsic or pe­ripheral proteins.