Re: What compound is formed by oxygen and iron after O2 diffuses the blood?

Rafaelina,

The iron in blood is carefully packaged into a protein called hemoglobin
(iron on its own is quite poisonous). Four similar globin chains (each
containing an iron atom) stick together forming the complete hemoglobin
molecule. Hemoglobin gives blood its red color. Oxyhemoglobin is bright
red, hemoglobin (without the oxygen) is a more blue color. The protein has
evolved so that it can easily bind oxygen reversibly, forming
oxyhemoglobin, where a molecule of oxygen is attached to the iron. This
happens in the lungs, where the oxygen concentration is high, then the
oxygen is released in tissues (for instance muscle) where the oxygen
concentration is low. These web pages show some pictures of what hemoglobin
looks like.

 http://www.people.virginia.edu/~rjh9u/hemoglob. http://www.umass.edu/microbio/chime/hemoglob/