What is Plasma membrane- Fluid mosaic model

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Plasma membranes are the outermost covering of a cell that separates it from the external environment does it defines a cell's physical and chemical boundaries. Other names of the plasma membrane are cell membrane, biomembrane, and living membrane.

  • Cellular membranes both the plasma membrane and original membranes consists of a bilayer of phospholipids in which other lipids and proteins are embedded.
  • This lipid and protein combination gives distinctive permeability qualities to a cell.
  • Plasma membranes are selectively permeable in nature and they have elasticity. They Are impermeable to most water-soluble molecules.
  • They are Dynamic in nature having a fluid structure and most of their molecules move in the plane of the membrane.
  • Composition lipid (major), protein (major), and carbohydrate minor.

The most acceptable model for plasma membrane was given by Jonathan singer and Garth Nicholson in 1972 was the lipid bilayer fluid mosaic model.

According to this model, the plasma membrane has lipid bilayers in which protein molecules are embedded. These lipids are primarily amphipathic phospholipids.
They have a hydrophilic polar head and two hydrophobic nonpolar tails. In between this phospholipid bi-layer along with proteins, small amounts of carbohydrates and cholesterol are also present. These proteins are of 3 types- Peripheral protein, Integral protein, and lipid-linked protein.