Is there any evolutionary reason for glucose being the "main" molecule used as a source of energy, beginning with glycolysis and subsequently cellular respiration (after being converted to two pyruvate molecules)? Or did this particular biochemical pathway arise "by fluke" early on in the history of life?
A colleague of mine told me that it was because as shown below, all of beta-D-glucose's hydroxyl substituents are all equatorially positioned (when in the correct chair conformation), which lends to its general stability.
Image taken from the Wikimedia Commons.
Could this have played a factor in the beginnings of energy metabolism, and if so, why?