There is but a single enzyme catalysed reaction in the human body known to generate carbon monoxide(CO) as one of its products.the enzyme that catatlyzes this CO producing reaction is
a.biliverdin reductase
b.coproporphyrinogen oxidase
c.heme oxygenase
d.protoporphyrinogen oxidase
e.uroporphyrinogen decarboxylase
C
heme is oxidized ,with the heme ring being opened by th endoplasmic reticulum enzyme,heme oxygenase.the oxidation steps requires heme as a substare,and any hemin(Fe 3+) is reduced to heme prior to oxidation by heme oxygenase.The oxidation occurs on a specific carbon producing the linear tetrapyrole biliverdin ,ferric ion(Fe3+). n CO.this is the only reaction in the body known to produce CO.Most of the CO is excreted thru lungs ,with the result that the Co content of expired air is a direct measure of the activity of heme oxidase in an individual >Biliverdin reductase(choice A) catalyzes the convertion of biliverdin to bilirubin.
Coproporphyrinogen oxidase (choiceB) protoporphyrinogen oxidase(choice D) n uroporphyrinogen decarboxylase (choice E) r all involved in the synthesis of heme n donot produce CO in the course of cartalyzing their reactions.