Re: how do mitochondria work ?

Mitochondria are the power-house of the living cell. The secret to their 
function lies in their microscopic structure (which you can find in any 
standard text book). 
Mitochondria are sub-cellular organelles having a double membrane bound 
structure. There are these enzymes called as ATPases, anchored to the 
inner membrane, which serve to synthesise small molecules called ATP 
(Adenosine Tri Phosphate). 
there is a difference in the hydrogen ion (H+) levels outside & inside of 
the inner membrane, generated by the aerobic metabolism of sugars and fats.
This difference serves as the driving force for the ATPases to synthesise ATP 
molecules. ATP molecules are energy carriers - they carry energy in the bonds 
that join the three phosphate (PO4) groups within the molecule. 
These molecules are then used as energy packets whenever energy is 
required for any cellular activity.