Final answer:
The plasma membrane is involved in cellular transport, cell signaling, and cell adhesion.
Step-by-step explanation:
The plasma membrane is involved in multiple activities within a cell. Three key activities in which the plasma membrane plays a role are:
- Cellular transport: The plasma membrane regulates the movement of substances in and out of the cell. It uses various transport mechanisms such as facilitated diffusion, active transport, and endocytosis/exocytosis to control the passage of molecules and ions.
- Cell signaling: The plasma membrane contains receptors that receive signals from outside the cell. These signals can be in the form of hormones, neurotransmitters, or other signaling molecules. The receptors transmit the signals to the cell's interior, initiating specific cellular responses.
- Cell adhesion: The plasma membrane plays a crucial role in cell adhesion, allowing cells to stick to one another and form tissues. It contains proteins called adhesion molecules that facilitate cell-to-cell interactions and help maintain tissue structure.