| − | (''biology'')A series of intracellular [[chemical]] [[reactions]] ensuing from the association of a [[transmembrane protein]] with an [[extracellular]] signal, resulting in a subsequent alteration at the [[second messenger]] level and leading to a modification at the [[regulatory]] level. | + | # {{sense|biology}} A series of intracellular [[chemical]] [[reactions]] ensuing from the association of a [[transmembrane protein]] with an [[extracellular]] signal, resulting in a subsequent alteration at the [[second messenger]] level and leading to a modification at the [[regulatory]] level. |