Question

Hormones thyroxine, adrenaline and the pigment melanin are formed from

• A. Tryptophan
• B. Glycine
• C. Tyrosine
• D. Proline

Answer 1

The correct option is C Tyrosine

The thyroid hormones triiodothyronine ($T_3$) and thyroxine ($T_4$) in the colloid of the thyroid also are derived from tyrosine.

In chemical terms, epinephrine is one of a group of monoamines called the catecholamines. It is produced in some neurons of the central nervous system and in the chromaffin cells of the adrenal medulla from the amino acids phenylalanine and tyrosine.

Melanin is produced by the oxidation of the amino acid tyrosine, followed by polymerization. The pigment is produced in a specialised group of cells known as melanocytes.

So, the correct answer is option C.