What is the main role of the cell membrane?

The primary function of the cell membrane is to control the movement of substances into and out of the cell. This selective permeability allows the cell to maintain a stable internal environment, which is essential for the proper functioning of cellular processes. The cell membrane consists of a phospholipid bilayer with embedded proteins that facilitate the transport of molecules. Some substances can pass freely through, while others require specific transport mechanisms, such as channels or carriers.

This role is critical because it enables the cell to take in essential nutrients, such as glucose and ions, and eliminate waste products. Additionally, the cell membrane plays a significant role in cell signaling and communication with other cells, further contributing to the overall homeostasis of the organism.

Other possible functions mentioned, such as energy production or regulating cell division, are associated with different cellular components and processes. Energy production occurs primarily in organelles like mitochondria, and cell division is governed by various factors and mechanisms within the nucleus and cytoplasm, not solely by the cell membrane itself. Providing structural support is also important, but that is more related to the cytoskeleton and extracellular matrix rather than the cell membrane.