Signaling -

A signaling molecule (ligand) binds to a specific receptor on the cell surface or inside the cell.

The receptor triggers a relay of intracellular molecules, often called a signaling cascade (e.g., using G-proteins or kinases). signaling

Signaling between cells in physical contact. A signaling molecule (ligand) binds to a specific

Nearby cells are targeted (e.g., neurotransmitters). often called a signaling cascade (e.g.

Long-distance signaling via the bloodstream (e.g., hormones).

Cell signaling is the complex process by which cells perceive and respond to their environment. It is essential for homeostasis, growth, and immune responses.