I was thinking about mitochondria, but I got sidetracked when I remembered Ling and his opinion about ATP. Here's how it went:
The vast majority of the energy production in our bodies occurs in our mitochondria. These are the tiny powerhouses which generate most of the high energy adenosine tri phosphate (ATP) on which we ultimately run our metabolism.
NB an aside; Gilbert Ling does not believe in ATP as an energy source for cells (though he thinks it is a crucial molecule), any more than he believes in the lipid bi-layer cell membrane or the sodium/potassium ATP pump. He is truly out on a limb with his "Association Induction Hypothesis" of life at cell and below cell level. A fruitcake, obviously. Except his ideas on the localisation of cell water around proteins led to the invention of the MRI scanner. If MRI scanners work, that cookie Ling is right. And almost all of modern physiology is wrong.
It is, for me personally, MUCH easier to think within the "normal" physiology of my education. But, because MRI scanners work, this is the equivalent of thinking that the table in front of me is "solid" when quantum mechanics tells me that it is anything but solid...
Now there's a thought.