which atom is involved in giving your heart energy to beat? carbon gold oxygen iron

This idea has been somewhat controversial. Why might O 2 bind in a bent fashion whereas CO bounds in a linear mode? Presumably, the protein could contribute to a similar destabilization of CO-bound hemoglobin. It may be that in a vaulted model complex, the CO simply can't stand up straight, so the complex is destabilized. However, when CO binds to a metal, it does so in a linear fashion. It is pretty well-established via other model studies, as well as direct study of oxyhemoglobin, that when oxygen binds to a metal such as iron, the Fe-O-O forms an angle of somewhere around 120 °. Is it possible that O 2 can fit inside but CO cannot? The domed or vaulted model compound suggests a protective covering for the oxygen binding site. What does that tell us about hemoglobin? It may be nothing, but it could be indicating another role for the surrounding protein in the hemoglobin molecule. For example, the one shown below has an M value closer to 0.005.

Not content to rest on their laurels, the Collman lab went back to the drawing board and developed lots of other model complexes. If our hemoglobin had an M value like that of the picket fence porphyrin, we would all be dead, poisoned by our own metabolic processes. CO is actually a product of the normal breakdown of heme molecules over time in the cell. There is a deeply problematic consequence of CO poisoning, however, that could be much worse if the M value in an organism was as high as in the picket fence porphyrin. Why worry about CO binding in these studies? Of course, carbon monoxide poisoning is a serious and potentially fatal condition. That means it is much poorer at binding O 2, relatively, than hemoglobin. However, the picket fence heme has an M value over 25,000. That means hemoglobin binds CO about 100 times better than it binds O 2. In hemoglobin, this value is about 100, although it will vary from one organism to another. The lower the M value, the greater the favorability for O 2 binding compared to CO binding.

Which atom is involved in giving your heart energy to beat? carbon gold oxygen iron