Which one of the following is a peptide hormone?
- Adrenaline
- Glucagon
- Testosterone
- Thyroxine
Answer
(2) Glucagon
Solution
Hormones are of three types by chemical nature:
Steroids – testosterone, estrogens, progesterone.
Amino acid derivatives – adrenaline (epinephrine), thyroxine.
Polypeptides / proteins – insulin, glucagon.
∴ Glucagon (a polypeptide of 29 amino acids secreted by the α-cells of the pancreas) is a peptide hormone.
Answer: (2)