Tyrosine is modified by tyrosine hydroxylase to form DOPA.
Oxytocin binds to oxytocin receptors in the uterine myometrium, which triggers the G-protein coupled receptor signal transduction cascade that causes increased intracellular calcium concentrations.
Serotonin is a result of tryptophan, a component of proteins, combining with tryptophan hydroxylase, a chemical reactor.
