Cell Membrane and Fluid Mosaic Model
Q. Explain the fluid mosaic model of Singer and Nicolson ? or Structure of cell membrane by the fluid mosaic model?
The structure of the cell membrane is explained by the fluid mosaic model of Singer and Nicolson.
According to this model cell membrane is consist of three parts:-
The structural framework of cell membrane is lipid by layer which consist of three types of lipid molecule:-
Phospholipid:- It is formed by phosphate and fatty acid. The outer part of the phospholipid layer is the head which made up of phosphate.
The inner part is the tail portion which consists of fatty acid, this part is hydrophobic. The hydrophobic head part faces the ECF outside the cell and ICF inside the cell.
Cholesterol:- Cholesterol molecules are arrangements to act the phospholipid in the membrane to provide structural stability to the cell membranes.
Glycolipid:– It is formed when lipid attached to the carbohydrate. Glycolipid present on the outer surface of the cell.
The protein layer of the cell membrane situated on either side of the lipid layer. These protein molecules are classified into two groups:-
- Integral Protein
- Peripheral Protein
Integral Protein:- The integral protein is also known as Trans-membrane Protein are tightly adheres to the cell membrane. These portion molecules are pass through the entire fitness of the cell membrane from one side to another side.
Peripheral Protein:- They are also known as Peripheral Membrane Protein. Peripheral protein does not penetrate the cell membrane but partially embedded in the outer and inner surface of the cell membrane.
The Carbohydrate layer is consists of 2-6o monosaccharide change they may be branched or straight.
Some carbohydrates are attached to the lipid called Glycolipid and some carbohydrates are attached to protein are called Glycoprotein.