2006-11-12 00:47:15 · 5 answers · asked by catalyst 1 in Science & Mathematics ➔ Chemistry
its not that the co bonds with the heamoglobin it forms a complex i.e it replaces the nitrogen atoms in heamoglobin to form the complex...CARBOXY HEAMOGLOBIN.. so we dont have the case of ...C reacting..
2006-11-12 01:56:35 · answer #1 · answered by indurti karthik 2 · 1⤊ 1⤋
The atom in CO has a partial negative charge and it can "donate" electrons to act as a ligand for the iron ion (Fe+2) in the hemoglobin group.That's why it binds more strongly to Fe+2 than O2 (which is a non-polar molecule) and causes poisoning. CN- which has a net negative charge binds even more strongly and is a more potent poison.
In CO2 it has a partial positive charge so that wouldn't be possible. Moreover for strereochemical reasons, the C of CO2 cannot reach Fe+2. CO2 binding to hemoglobin is actually through binding to the free amino groups of hemoglobin and not to the Fe+2.
In fact the protein structure is such that a distal histidine group forces even O2 and CO to bind at an angle and thus less strongly to Fe+2. Otherwise Fe+2 would react with O2 instead of transporting it.
2006-11-13 07:53:30 · answer #2 · answered by bellerophon 6 · 1⤊ 0⤋
I'm a little rusty on Chem but I'm pretty sure it's because the 2 Os take up all the electrons for binding in the CO2. Where as the C atom in co has available electrons to bind to the Hemoglobin.
2006-11-12 08:50:12 · answer #3 · answered by Ericka 2 · 1⤊ 0⤋
basically, haemoglobin is a compound containing Fe, ie., iron and N(nitrogen) etc. the rings containing Fe and N are called Porphyrin rings. the Fe atom is at the centre, at which the Oxygen atoms are bound, when they are transported from one place to another in the body.
in CO, the C has a lone pair of electrons, which it can donate to an atom with an empty valence orbit. in CO2, there are no lone pairs present.
so, when CO is inhaled, it combines with Haeme, via a co-ordinate covalent bond forming "Carboxy Haemoglobin" which is toxic, causing monoxide poisoning.
but CO2 cant form such a co-ordinate covalent bond and thus cant form a complex like with CO.
hope that explains your doubt.....
2006-11-13 08:43:06 · answer #4 · answered by sameer 2 · 0⤊ 0⤋
It is not the C atom binding with hemoglobin, it is CO compound replacing O2.
2006-11-12 09:12:59 · answer #5 · answered by Anonymous · 0⤊ 0⤋