Which term is used to describe the layer surrounding a cell?

The term that accurately describes the layer surrounding a cell is the cell membrane. The cell membrane, also known as the plasma membrane, serves as a protective barrier that regulates the movement of substances in and out of the cell. It is primarily composed of a phospholipid bilayer with embedded proteins that facilitate communication and transport, thereby maintaining the homeostasis of the cell.

In contrast, protoplasm refers to the living contents within a cell, including the cytoplasm and the nucleus, rather than the layer around the cell. Cytoplasm is the gel-like substance within the cell membrane that houses organelles, while the nucleus is the control center of the cell containing genetic material. Understanding these distinctions reinforces the importance of identifying the correct terminology relating to cell structure and function.