receptor–effector coupling

Receptor-effector coupling is the process by which a cell responds to a chemical signal. This begins when a signaling molecule, like a hormone or neurotransmitter, binds to a specific receptor on the cell's surface or within the cell. This binding event triggers a cascade of intracellular events.

These events can involve:
* Directly opening or closing ion channels in the cell membrane, altering electrical properties.
* Activating or inhibiting enzymes that produce or degrade intracellular signaling molecules, often called second messengers like cAMP or calcium ions.
* Regulating gene expression, which affects protein synthesis.

These internal changes ultimately alter the cell's behavior, leading to a specific physiological response.12