Synthesis of Thyroid Hormones
Sequence of I2 trapping, I2 oxidation and organification (formation of mono- and diiodothyrosine), condensation into triidotyronine (T3) and thyroxine (T4), storage and release of hormones as colloid (degraded by lysosomal proteases)
T4 and T3 are primarily bound to TBG; 1/3 of the binding sites on the binding protein are occupied by hormones; the remainder is free metabolically active hormone.