Amino Acid Derivatives (iii)

• Thyroid hormones are thyroxine (T₄) and 3, 5, 3' triiodothyronine (T₃) (iodinated derivatives of tyrosine).
• They are synthesised by the thyroid glands.
• T₄ and T₃ are stored as thyroglobulin (a large glycoprotein) before release.
• They are lipid-soluble and able to diffuse through cell membranes.