Question

Which of the following is false?

(a) Heme consists of a complex organic ring structure, protoporphyrin

(b) Protoporphyrin is bound to a single iron atom in its Fe^+3 state

(c) Iron atom has 6 coordination bonds

(d) Heme is found in a number of oxygen transporting proteins

The question was asked by my college professor while I was bunking the class.

This intriguing question originated from Reversible Binding of a Protein to a Ligand: Oxygen-Binding Proteins topic in chapter Three Dimensional Structure Of Proteins and Protein Function of Biochemistry

Answer 1

Correct choice is (b) Protoporphyrin is bound to a single iron atom in its Fe^+3 state

Easiest explanation: Protoporphyrin is bound to a single iron atom in its Fe^+2 state.