[robbiep]

I think you mean carbon instead of oxygen, and it's 2 at a time, not one at a time.

Your analogy is roughly correct but in the base, reductionist biochemistry of which the body functions, you have fats (chains of carbons with hydrogens on them - directly burned this way), carbs (basic form C6H12O6) which are also directly burnt this way with water coming off, and protein, which has occasional nitrogen atoms and some sulphur atoms. Proteins can also carry metals - so bits of iron or copper or other things we need to make some proteins function correctly are 'carried' into the intestinal system this way. The only other thing we really need is lots and lots of Phosphate, which we take in largely through consumption of DNA in things we eat

If proteins are to be burnt in mitochondria the nitrogens are converted to urea and excreted.

Vitamins are just arrangements of carbon atoms with the occasional nitrogen and oxygen and hydrogen around. Some have a single copper or zinc atom there too.

We really don't use any more than this, our body literally does just run on carbon. To complete your statement, although there is more in food than just carbon, there really isn't much that we are interested in (biochemically speaking) than the carbon, although the body has uses for some of the myriad forms that are created in other plants and animals that we can't synthesise ourselves.

[Mz]

You know, I feel really crappy today. I am not finding anything that readily matches my recollection of the process, though glycolysis and atp come up in my search and that partially matches my memory. Maybe you could link me to something that fairly clearly shows what you mean? My understanding is "burn" = "consume oxygen".

Thanks.

[robbiep]

burning is oxidation, and oxidation requires O2 (although it doesn't always require O2 -oxidation chemically speaking is stripping Electrons and Hydrogen atoms out of a molecule. Which liberates energy.

So you are right. My take on your comment was that you had confused Carbon and oxygen... Since Carbon is the fuel and Oxygen is the oxidising agent , and the convention is basically to talk about the fuel as the one that is being consumed.

I don't have any videos or anything but if you are interested I have attached a link to my old biochemistry notes which, especially if you have a rusty background in anything resembling science, should hopefully jump you along a bit

http://sdrv.ms/SHJQHs

[Mz]

Thanks. I will try to look for something some other time to clarify my understanding. Some time when I feel less crappy.