In a recent post I talked about a metabolic poison that can decouple electron transport and oxidative phosphorylation.  You may be interested to know that this process is a known mechanism in infants.  This is not mediated by the same metabolic poison as I mentioned before, but rather by a naturally produced protein called thermogenin.  This protein causes the uncoupling of electron transport and oxidative phosphorylation in a cell’s mitochondria.  Check back a few posts for the mechanism if you’re interested.

So where does this take place?  If it took place in all cells (like if someone were to take that metabolic poison) the infant would be unable to survive.  Infants have specialized cells called brown adipose tissue or “brown fat” where this takes place.  These cells have many small fat vacuoles and mitochondria.  The normal fat found in adults is referred to as white fat.  Adults don’t have much (if any) brown fat.  By decoupling electron transport and oxidative phosphorylation the cell redirects the metabolic energy.  This results in the generation of heat and infants don’t need to shiver.  Neat, huh?