gen-explain-the-structure-of-the-cell-membrane-as-you-would-to-a-4ae3

Explain the structure of the cell membrane as you would to a capable student, in 3-4 sentences.

The cell membrane is primarily composed of a **phospholipid bilayer**—two layers of phospholipid molecules arranged with their hydrophobic (water-repelling) tails facing inward and their hydrophilic (water-attracting) heads facing outward toward the watery environments inside and outside the cell. Embedded within and attached to this bilayer are various **proteins** that serve as channels, receptors, and transporters, while **cholesterol** molecules nestled between phospholipids help maintain membrane fluidity and stability. This arrangement, called the **fluid mosaic model**, allows the membrane to be selectively permeable—controlling what enters and exits the cell while remaining flexible enough for the cell to change shape and function. The membrane essentially acts as a dynamic barrier that both protects the cell and enables communication with its environment.