The thyroid hormone thyroxine (T4) is derived from?
Threonine
Tyrosine
Thiamine
Tryptophan
Thyroxine is a derivative of tyrosine. It is formed by the iodination and joining of peptide-linked tyrosyl residues of thyroglobulin. Proteolysis of thyroglobulin yields thyroxine. Thyroxine is also called tetraiodothyronine, or T4, because of the four iodine atoms of the thyroid hormone. Ref:Weil P. (2011). Chapter 41. The Diversity of the Endocrine System. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds),Harper's Illustrated Biochemistry, 29e.