Question

The hormone that triggers the flight-or-fight response, epinephrine, is derived from tyrosine, and the hormone that regulates circadian rhythms, melatonin, is derived from tryptophan. What class of hormone are these?

a) Peptide Hormones
b) Steroid Hormones
c) Amino Acid-Derived Hormones
d) Protein Hormones

Answer 1

Epinephrine and melatonin are amino acid-derived hormones, originating from tyrosine and tryptophan, respectively, and fall into the class of amine hormones.

Step-by-step explanation:

The hormones epinephrine, which is involved in the fight-or-flight response, and melatonin, which regulates circadian rhythms, are both derived from amino acids. Epinephrine originates from the amino acid tyrosine, and melatonin comes from tryptophan. These hormones belong to a class known as amino acid-derived hormones or amine hormones. Epinephrine and norepinephrine, which are catecholamines, are synthesized in the medulla of the adrenal glands, while melatonin is produced by the pineal gland in the brain. This class also includes thyroid hormones, such as thyroxine. Unlike peptide hormones, which are polypeptides, and steroid hormones, which are derived from cholesterol, amino acid-derived hormones are small molecules originating from single amino acids.