Hydrochloric Acid (HCl) is produced by the stomach and has the job of breaking down proteins. If you make plenty of HCl, then the body can adequately digest protein. If not, protein digestion is compromised.
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.
