Signaling Molecules and Cellular Receptors

Cellular communication ensures regulation of biological processes within various environments from single-celled to multicellular organisms.

The major types of signaling mechanisms that occur in multicellular organisms are paracrine, endocrine, autocrine, and direct signaling.

Receptors, either intracellular or cell-surface, bind to specific ligands, which activate numerous cellular processes.

Signaling molecules are necessary for the coordination of cellular responses by serving as ligands and binding to cell receptors.