Which structure primarily composes the fluid mosaic model of the cell membrane?

The fluid mosaic model of the cell membrane primarily consists of a lipid bilayer with embedded proteins. This model illustrates how the membrane is not a rigid structure, but rather a dynamic and flexible composition. The lipid bilayer is formed by phospholipids, which have hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails. This arrangement results in a bilayer that allows the hydrophilic heads to face the aqueous environment both inside and outside of the cell, while the hydrophobic tails face inward, away from the water.

In addition to the phospholipids, various proteins are interspersed throughout the bilayer. These proteins can serve many functions, including acting as receptors, channels, and transporters, or providing structural support. The term "mosaic" refers to the patchwork of these proteins that float in or on the fluid lipid bilayer, creating a diverse and functional interface between the cell and its environment.

The other options do not accurately describe the cell membrane structure. Cellulose fibers and carbohydrates are not the primary components of cell membranes in animal cells, as cellulose is typically found in plant cell walls. Fatty acid chains and cholesterol crystals do not reflect the arrangement and functionality represented in