Published in Henry Rzepa's Blog
Author Henry Rzepa
Respiratory pigments are metalloproteins that transport O 2 , the best known being the bright red/crimson coloured hemoglobin in human blood. The colour derives from Fe 2+ at the core of a tetraporphyrin ring. But less well known is blue blood , and here the colour derives from an oxyhemocyanin unit based on Cu 1+ (the de-oxy form is colourless) rather than iron.