Solution

Hormones belong to different chemical groups:
Proteins and peptides: insulin, glucagon, pituitary and hypothalamic hormones.
Steroids: cortisol, aldosterone, testosterone, estradiol, progesterone.
Biogenic amines (amino acid derivatives): epinephrine, norepinephrine and thyroxine. (Iodothyronines are sometimes listed separately.)
So chemically hormones are proteins, steroids and biogenic amines.

Concept Classes of hormones

Chemical nature of hormones in past papers

2 questions from this chapter have appeared across 2 exam years.