What is the function of ligands within cellular interaction?

Ligands play a crucial role in mediating signaling between cells, which is essential for various physiological processes. They are molecules that bind specifically to receptors, which are usually proteins located on the surface of cells or inside them. This binding initiates a series of biochemical events that can alter cellular activities, trigger responses, or communicate information between cells.

For example, in the immune system, ligands can help transmit signals that activate immune responses when pathogens are detected. In the nervous system, neurotransmitters act as ligands that facilitate communication between neurons. Thus, ligands function as key messengers in signaling pathways that help to coordinate complex responses and maintain homeostasis within the organism.