Answer:
The completed sentences are given below.
Explanation:
Haemoglobin is a complex protein consists of heme and globin. Heme contains iron as central element.
The prosthetic group of hemoglobin and myoglobin is heme.
The organic ring component of heme is porphyrin.
Under normal conditions, the central atom of heme is Fe²⁺.
In deoxyhemoglobin the central iron atom is displaced 0.4 A out of the plane of the porphyrin ring system.
The central iron atom has 6 bonds: 4 to nitrogen atoms in the porphyrin, one to a histidine residue and one to oxygen