What unusual property do cytochromes have in common with hemoglobin or myoglobin?

The unusual property that cytochromes have in common with hemoglobin or myoglobin is that all of them contain heme groups. Cytochromes are heme-containing electron transport enzymes which are essential for the oxidative metabolism necessary to generate adenosine triphosphateas well as for the oxidative degradation of drugs and endogenous substrates. 

What’s the

Aneutral atom must have the same number of neutrons and protons? no, they must have the same number of protons and electrons