Definition:
In biology, a precursor is a substance from which another substance is formed. For example, the amino acid tyrosine is a precusor of the neurotransmitters norepinephrine, dopamine and epinephrine, while the amino acid tryptophan is a precursor of the neurotransmitters serotonin and melatonin.
In biology, a precursor is a substance from which another substance is formed. For example, the amino acid tyrosine is a precusor of the neurotransmitters norepinephrine, dopamine and epinephrine, while the amino acid tryptophan is a precursor of the neurotransmitters serotonin and melatonin.
Pronunciation: pree-KUR-ser
