Biochemistry/Chemistry of hormones

Hormones are classified into three types depending upon their biochemical/chemical nature and composition. They are:

1. Steroid hormones: These hormones contain steroid nucleus and they are derived from cholesterol. Sex hormones, corticosteroids, testosterone, estrogen etc . are examples of steroid hormones.
2. Peptide/protein hormones: These hormones contain amino acids linked by peptide bonds. Examples are insulin, glucagon, growth hormone etc.
3. Amino acid derived hormones: These hormones are directly derived from the amino acids. For example thyroid hormones are derived fron the amino acid tyrosine.