Ligands, which are produced by signaling cells and interact with receptors in or on target cells, come in many different varieties. Some are proteins, others are hydrophobic molecules like steroids, and others yet are gases like nitric oxide.

What are ligands made of?

In biochemistry, a ligand is any molecule or atom which binds reversibly to a protein. A ligand can be an individual atom or ion. It can also be a larger and more complex molecule made from many atoms. A ligand can be natural, as an organic or inorganic molecule.

What causes a ligand to be released?

Similar to a prior example, when there is a lot of glucose, the ligands may be released to send the message to the liver to secrete more insulin. Other examples of stimuli include the age of the cell, light, smells, taste, and touch.