What is the life function of cell membrane?

The cell membrane, also known as the plasma membrane, is a crucial component of all living cells. Its primary function is to act as a barrier between the cell's internal environment (cytoplasm) and the external environment. This barrier is selectively permeable, meaning it controls which substances can enter and exit the cell.

Here are some key life functions of the cell membrane:

* Regulation of transport: The cell membrane regulates the passage of substances like nutrients, water, ions, and waste products. It does this through various mechanisms including:

* Passive transport: This doesn't require energy and includes diffusion, osmosis, and facilitated diffusion.

* Ενεργή μεταφορά: This requires energy (ATP) and involves pumps that move molecules against their concentration gradient.

* Maintaining cell shape and structure: The cell membrane provides structural support and helps maintain the cell's shape.

* Κυτταρική σηματοδότηση: The cell membrane contains receptors that bind to signaling molecules (like hormones) and initiate specific responses within the cell.

* Cell recognition: The cell membrane contains surface markers (like glycoproteins) that allow cells to recognize each other and interact appropriately.

* Protection: The cell membrane acts as a barrier against harmful substances and helps protect the cell's internal environment.

In essence, the cell membrane is a dynamic and essential structure that plays a vital role in the survival and functioning of all living cells.