Explain fluid mosaic model of cell membrane.

The fluid mosaic model describes the structure of the cell membrane as a dynamic and flexible arrangement of lipids and proteins. According to this model, the membrane is primarily composed of a phospholipid bilayer with embedded proteins that move laterally, giving it a fluid-like nature.

Each phospholipid molecule has a hydrophilic (water-attracting) head and hydrophobic (water-repelling) tails. The heads face the aqueous environments inside and outside the cell, while the tails face inward, forming a stable bilayer that acts as a barrier.

Proteins are distributed unevenly within this lipid matrix, creating a "mosaic" pattern. These proteins perform various functions, including transport (channels and carriers), cell communication (receptors), and enzymatic activity.

Cholesterol molecules are also present in animal cell membranes, helping to maintain fluidity and stability by preventing the membrane from becoming too rigid or too fluid under temperature changes.

The fluid nature of the membrane allows components to move within the layer, enabling processes such as cell signaling, transport, and membrane repair.

Overall, the fluid mosaic model explains how the cell membrane maintains structural integrity while remaining flexible and functionally active.