The Fluid Mosaic Model, proposed by S. J. Singer and Garth Nicolson in 1972, describes the structure of biological membranes. It suggests that the cell membrane is a dynamic and fluid structure where lipid molecules form a bilayer, and proteins are embedded within it. The model helps explain the membrane's selective permeability, fluidity, and the ability to accommodate various functions. At the core of the model is the lipid bilayer, composed primarily of phospholipids. Each phospholipid molecule has a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. The hydrophobic tails face inward, shielded from water, while the hydrophilic heads are exposed to the aqueous environment inside and outside the cell. This arrangement creates a semi-permeable membrane that controls the movement of substances into and out of the cell. The lipid bilayer is not static; rather, it behaves like a fluid. Lipids and proteins are not rigidly fixed in