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What is carbon monoxide poisoning and why is it lethal to humans? What is the chemical reaction that occurs in the body when carbon monoxide is inhaled?
Question Date: 2008-09-24
Answer 1:

Good question. Let me explain a little about blood first. Your red blood cells (rbc's) are basically little bags of a substance called hemoglobin. In fact, rbc's are the only cells in your body without nuclei; they lose them when they mature so that more hemoglobin can be packed into the cell. Hemoglobin molecules are little oxygen carriers. Each molecule has four "seats" that can be filled with oxygen. They can pick up oxygen in your lungs and deliver it all over your body. Every cell needs a supply of oxygen.

Carbon monoxide (CO) is very dangerous because it sticks to your hemoglobin better than oxygen does. It "hogs the seats" so that oxygen can't get a ride. And those CO molecules keep riding around, never giving their seats up to the oxygen. This means there's no way to get oxygen to your brain, heart, or other cells and those cells start to die. The chemical reactions that stop happening when there's no oxygen are the ones that make ATP, the form of energy that all of our cells use.

You can't see, smell, or taste CO, so it's very dangerous. Things that burn fuel (furnaces, cars, barbeque grills, etc.) produce CO, and that's why they have to be ventilated to the outside.

Do you think people with CO poisoning get better by themselves?

How do you think people with CO poisoning are treated?

People who don't have enough hemoglobin have a form of anemia. What do you think some of the symptoms might be?

Would they be like symptoms of mild CO poisoning?

Thanks for asking,

Answer 2:

The problem with carbon monoxide (CO) is that it inhibits your ability to distribute O2 (oxygen). Hemoglobin, a protein in your red blood cells, binds oxygen in your lungs, and distributes oxygen throughout your body. Hemoglobin has a very high affinity for oxygen. However, it has a HIGHER affinity for CO. The usual function of hemoglobin is to bind oxygen (O2) and take it to a place in the body that needs oxygen, and then releases the oxygen. When hemoglobin binds CO, it binds so tightly that it will not let go. Therefore, the hemoglobin that binds CO becomes 'poisoned' and can no longer bind oxygen, destroying its function. Then, parts of your body do not receive the essential oxygen, and effectively suffocate.

hem + O2 <--> (hem-O2)
hem + CO ---> (hem-CO)
Best wishes,

Answer 3:

Carbon monoxide poisoning occurs after carbon monoxide gas is inhaled. It causes headaches, fatigue, depression, dizziness and can lead to more serious complications if exposure is chronic (i.e. heart disease and death.) Carbon monoxide displaces oxygen from hemoglobin (oxygen carrying protein in the blood) and also effects myoglobin (primary oxygen carrying pigment of the muscle) and cytochrome oxidase (enzyme in the electron transport chain in mitochondria.) It removes oxygen in hemoglobin and myoglobin, depleting your oxygen source to your body. I'm not sure where carbon monoxide binds cytochrome oxidase but it probably knocks out its function for generating ATP. The electron transport chain makes oxidative phosphorylation possible and oxidative phosphorylation is a major source of ATP. Thus carbon monoxide would affect the ability of your cells to generate energy (ATP.) I don't know if there is a word for this chemical reaction in particular. However, I suppose displacement of oxygen binding by carbon monoxide could be considered a type of "inhibition." Unfortunately as I don't know where exactly carbon monoxide binds I can't tell you whether it is a competitive (where oxygen competes for the same binding site as carbon monoxide) or non-competitive (where carbon monoxide binds at a different site but changes the conformation of hemoglobin such that oxygen can't bind) inhibition. Hope this helps!

Answer 4:

Normally, when you breathe, the oxygen is taken into your lungs where it enters your blood and is carried throughout your body by the protein hemoglobin. Hemoglobin is a protein with an Iron-Heme center. This Fe-Heme binds oxygen very strongly. When you breathe in carbon monoxide, the CO also binds to hemoglobin. It binds so strongly that is keeps oxygen from binding as well. Over time, if you breathe enough carbon monoxide, it binds to all of the hemoglobin in your body, and you no longer have enough oxygen in your blood.

Answer 5:

Carbon monoxide bonds to oxygen receptors in the human body more strongly than does oxygen itself. I believe the receptors in particular are in the brain, not the hemoglobin in the blood, but I am not sure. Because of the strength of the bond, the oxygen cannot then get into the tissues that need it, and said tissues asphyxiate.

Answer 6:

CO bonds where normally oxygen does bonds in the hemoglobin molecule. So, CO saturates the molecular site that USUALLY accommodates the oxygen. CO prevents the oxygen from getting into the molecules, in a sense. Get in.

Answer 7:

There really isn't much of a chemical reaction with carbon monoxide poisoning. Carbon monoxide and oxygen molecules both have 2 atoms. Carbon monoxide binds to hemoglobin in our red blood cells [erythrocytes is their scientific name]. With carbon monoxide bound to hemoglobin where oxygen is supposed to bind, our bodies don't get the oxygen they need. That's how carbon monoxide kills.

Hemoglobin is a protein with a special molecule called heme, with an iron atom at the center, where oxygen and carbon monoxide can bind.

Best wishes,

Answer 8:

The answer to your question involves hemoglobin, the protein that is responsible for carrying oxygen in red blood cells. The oxygen that we breath is not very soluble in liquids like blood. So to facilitate the transport of oxygen from our lungs to the cells in the rest of our body, red blood cells have high concentrations of the protein hemoglobin. Hemoglobin has a high affinity for oxygen, so when blood moves through the lungs, each molecule of hemoglobin binds to an oxygen molecule, allowing the blood to load up a much higher concentration of oxygen than it otherwise would. Then when those blood cells move to a different part of the body where the cells have relatively low concentrations of oxygen, the oxygen leaves the hemoglobin molecule and diffuses into the cells.The problem with carbon monoxide (CO) is that hemoglobin actually has a much higher affinity for CO than for oxygen. So when you breathe in CO, your hemoglobin molecules get loaded up with CO instead of oxygen, and no oxygen can be carried to the cells in your body. After a while, the cells start to die if they don't get enough oxygen, and this is what kills you. The only way to reverse this process is to breath in oxygen at a very high concentration - only then will the hemoglobin start to bind to oxygen instead of CO.

So the standard treatment for carbon monoxide poisoning is to breathe in 100% oxygen (remember that regular air is only about 20% oxygen). After a while, all of the hemoglobin molecules start to bind to oxygen again instead of CO, and you eventually exhale all of the CO that was breathed in.

Thanks for asking a good question!

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