Question

Which respiratory pigment contains Fe, but green in colour?

• A. Haemocyanin
• B. Haemoglobin
• C. Chlorocruorin
• D. None of the above

Answer 1

Answer: (C)

Chlorocruorin

Chlorocruorin is an oxygen binding hemeprotein present in the blood plasma of many annelids. It's affinity for oxygen is weaker than that of most haemoglobin. Chlorocruorin is noted for appearing green in dilute solutions. It is a hemeprotein, the heme contains a reduced iron atom, $F{e}^{2+}$ in the center of a highly hydrophobic, planar, porphyrin ring. Hence, option C is correct answer.