Here's why:
* Phospholipids are amphipathic: This means they have a hydrophilic (water-loving) head and a hydrophobic (water-fearing) tail.
* Cell membranes are selectively permeable: They need to control what enters and exits the cell, and phospholipids create a barrier that allows for this.
* Phospholipid bilayer: Phospholipids arrange themselves in a double layer with the hydrophilic heads facing the watery environments inside and outside the cell, while the hydrophobic tails face each other in the center.
This structure creates a flexible and dynamic barrier that is essential for the survival of all cells.
