Pituitary and Thyroid Physiology · Physiology

Thyroid peroxidase (TPO) is a multifunctional enzyme. Which of the following is NOT a role of TPO?

  1. Oxidation of iodide to reactive iodine
  2. Organification of iodine onto tyrosine residues of thyroglobulin
  3. Coupling of iodotyrosines to form T3 and T4
  4. Proteolysis of thyroglobulin to release free hormones
Show answer and explanation

Correct answer: Proteolysis of thyroglobulin to release free hormones

TPO is responsible for oxidation, organification, and coupling. The release of free T3 and T4 from thyroglobulin, however, requires endocytosis of the colloid and subsequent proteolysis by lysosomal enzymes.

Difficulty: Medium Question 37 of 40

Practice all 40 Pituitary and Thyroid Physiology questions

Keep practicing

More Pituitary and Thyroid Physiology questions