What is the basic structure of the cell membrane called?

The basic structure of the cell membrane is known as the phospholipid bilayer. This structure consists of two layers of phospholipids, which are molecules that have a hydrophilic (water-attracting) "head" and two hydrophobic (water-repelling) "tails." The arrangement of these phospholipids creates a barrier that is selectively permeable, allowing certain substances to pass in and out of the cell while keeping others contained.

The hydrophilic heads face outward, towards the aqueous environments both inside the cell and outside, while the hydrophobic tails face inward, shielding themselves from water. This configuration is essential for maintaining the integrity of the cell and supporting various functions, such as communication and transport.

The term "fluid mosaic model" describes the overall structure of the cell membrane, incorporating the phospholipid bilayer along with proteins, cholesterol, and carbohydrates that float within or on the bilayer. However, the question specifically asks for the basic structure, which is the phospholipid bilayer itself. Other choices like "cell wall" refer to a different cellular structure found in plant cells, and "protein channel" is a component that exists within the membrane but does not represent the membrane's basic structure.