Energy is stored in a molecule called
adenosine triphosphate (ATP).
There should be some familiar pieces here.
Adenine is one of the nucleic acid bases.
Ribose is the middle piece of RNA.
Phosphates also appear in RNA.
So ATP, amazingly, looks a lot like RNA.
ATP
has
more phosphates, and you don't make
a polymer out of them.
Do you think it could be a coincidence that two
critically important biomolecules have
very similar structures and compositions while
having totally different uses?