Biochemistry Biological role of metallothioneins is to sequester harmful metal ions. These bind which of the following ions? A Cd++, Cu++ & Zn++ B Al+++, Hg++ & NH4+ C Pt++, As+++ & P04 D Fe+++, Na+ & K+ 💡 Explanation Biological role of metallothioneins is to sequester harmful metal ions. These bind which of the following ions? ✓ Correct Answer: A. Cd++, Cu++ & Zn++