Which biochemical event does NOT take place during thyroid hormone synthesis?
A) One monoiodotyrosine molecule combines with one diiodotyrosine molecule to form one tri-iodothyronine molecule.
B) Two iodine molecules combine with one tyrosine molecule to form one diiodotyrosine molecule.
C) Two diiodotyrosine molecules combine to form one molecule of thyroxine.
D) Four iodine molecules combine with one tyrosine molecule to form one tetraiodothyronine molecule.

Question

Quizplus · Accepted Answer

Thyroid hormone synthesis involves the iodination of tyrosine residues on thyroglobulin, forming monoiodotyrosine (MIT) and diiodotyrosine (DIT). Two DIT molecules combine to form thyroxine (T4), and one MIT and one DIT combine to form triiodothyronine (T3). The statement in choice D is incorrect because four iodine molecules do not directly combine with one tyrosine molecule to form T4; rather, it is the combination of iodinated tyrosines that leads to hormone formation.

Which Biochemical Event Does NOT Take Place During Thyroid Hormone