Haemoglobin

[lisafaustina]

Do you have to know all the haemoglobin stuff ? It's not in my textbook so I know nothing about it. What are the main points you need to know about it?

[slothpomba]

I think its more of an example than something that is written into the study design.

Basically (I dont have my text book near me so i may be totally wrong):

• Haemoglobin is a protein in your red blood cells which "holds" oxygen

• Haemoglobin reacts with oxygen to form Oxyhaemoglobin  - It is in this form oxygen is transported in your body
• The air you breathe has a realitvely high concentration of oxygen, applying le chaterliers principal, this would push the reaction to the right, causing the formation of oxyhaemoglobin.
• haemglobin + oxygen oxyhaemoglobin

• Carbon monoxide is much more "attracted" or binds much more strongly to the haemoglobin in your cells than oxygen
• Because of this huge ability of carbon monoxide to bond to your haemoglobin , even a small amount of carbon monoxide can cause a major shift in the equilibrium (It binds 234 times stronger than oxygen to your haemoglobin)
• Carbon monoxide and haemoglobin bond to form carboxyhaemoglobin
• Since carbon monoxide bonding with haemoglobin "uses up" the supply of haemoglobin, according to le chateliers since the haemoglobin concentration drops(see reaction below), there is in an increase in the back reaction, breaking down oxyhaemoglobin back to haemoglobin and therefore reducing how much oxygen you have (oxygen is important!)
• haemglobin + oxygen oxyhaemoglobin

• One of the treatments for carbon monoxide poisoning is administering high concentrations of oxygen
• This causes more oxyhaemoglobin to be formed (forward reaction) and more oxygen to be supplied from the person, oxygen also takes up the "spots" on which carbon monoxide used to be stored, releasing it [CO that is] (half-life of carbon monoxide is 320 minutes when a person is breathing normal air but 80 minutes if they are breathing a higher concentration of oxygen (think mask in a hospital) )
• Note "Oxygen" represented in these equations can not be used by the body in a sense, it must be in the form of "Oxyhaemoglobin" to be able to oxygenate the person
• Carbon Monoxide eventually is released from your red blood cells (it doesn't permanently bind)

The treatment as i understand it (open to correction) generally works in this sort of a fashion:

• Haemoglobin + Carbon Monoxide Carboxyhaemoglobin  (This occurs when CO is breathed in, Carboxyhaemoglobin is formed)
• haemglobin + oxygen oxyhaemoglobin (Oxygen is administered, causing the reaction to shift to the right and join with haemoglobin to make oxyhaemoglobin. Since oxygen is joining with haemoglobin, the amount of haemoglobin drops)
• Haemoglobin + Carbon Monoxide Carboxyhaemoglobin (Since there is little haemoglobin due to the above, the reverse reaction occurs, breaking down carboxyhaemoglobin, releasing the poisonus carbon monoxide)

Hope i could help  
-kingpomba

[sillysmile]

probably irrelevant but anyway:
haemoglobin is the polypeptide protein (of quaternary structure) that is attached to iron which binds to and transports oxygen. 
it is part of red blood cells.

[8039]

You also need to know that oxygen therapy reverses the reaction of carbon monoxide and hemoglobin as an addition of a product shits equilibrium towards the reverse reaction.

[shinny]

As kingpomba pointed out, I'm fairly certain it's just an explanatory case to illustrate some of the concepts of equilibrium so exact details aren't needed. If it does come up on the exam, it'd have a heap of stimulus material with it. However, it's a good idea to familiarise yourself with the haemoglobin system in case it does come up on the exam and this allows you to quickly jump into the question without needing to spend time understanding it.

[slothpomba]

You also need to know that oxygen therapy reverses the reaction of carbon monoxide and hemoglobin as an addition of a product shits equilibrium towards the reverse reaction.

Thanks for reminding me, i add info on treatments