Questions & Answers

Which of the following hormones is derived from single amino acid?
A) Thyroxin
B) Oxytocin
C) Estradiol
D) Epinephrine

Answer Verified Verified
Hint: A hormone signaling molecule that is produced by the glands in higher organisms. The hormones regulate the physiology and behavior of the individual. Hormones circulated to the target organs through the circulatory system.

Complete Answer:
- Amino acid-derived hormones are those which are synthesized from the amino acids. Tyrosine and tryptophan are two amino acids, which are generally used in the biosynthesis of such hormones.
- The name of an amino acid-derived hormone ends with the suffix ‘ine’.
- Catecholamine such as epinephrine and norepinephrine, which are synthesized in the medulla of the adrenal glands is a classic example of amino acid-derived hormones. Another example is thyroxine, which is produced by the thyroid gland.

So, ‘Epinephrine’ is the correct answer.

Additional information: Based on the chemical class of hormones, hormones are classified in the following classes,
- Steroid hormones-Estradiol
- Eicosanoids- Hormones made from lipids, kinds of fats.
- Amino acid-derived- Thyroxine, epinephrine, nor-epinephrin
- Peptides, polypeptides, and protein hormones - oxytocin, small peptide hormones such as TRH and vasopressin.

- Both epinephrine and thyroxine are amino acid-derived hormones. Both are derived from tyrosine. But, iodine is also required along with tyrosine to synthesize thyroxine.
- Estradiol is a steroidal hormone. Estradiol is a female sex hormone produced by the ovaries, adrenal glands and also the placenta during pregnancy.
- Oxytocin is a peptide hormone. It is normally produced in the hypothalamus and released by the posterior pituitary. It plays a role in behavioral aspects such as social bonding.