Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
A signaling molecule is a molecule that is responsible for transmitting information between cells, tissues, or organs in an organism. It can initiate various cellular responses and regulate physiological processes.
Related terms
Receptor: A receptor is a protein located on the surface of cells that binds to specific signaling molecules (ligands), initiating a response within the cell.
Hormone: Hormones are specialized signaling molecules produced by glands in multicellular organisms. They travel through the bloodstream to target cells and regulate various physiological functions.
Neurotransmitters are signaling molecules released by nerve cells (neurons) to transmit signals across synapses to neighboring neurons or target cells. They play crucial roles in communication within the nervous system.