The point is that at multiple levels, biological functions are operating at the molecular and/or atomic level. The ATP/ADP reaction is another that comes to mind, though it's an energetic transformation involving cleaving/joining of a single atom from a molecule.

As for proofing methods: sometimes a transcription is in error. What then? The problem may be caught further upline: a protein is synthesized incorrectly and destroyed, a cell behaves improperly and the body's immune responses remove it, an imperfect embryo is formed and is reabsorbed or stillborn.

None of which denies the fundamental fact that biological processes occurring at the molecular/atomic level are in fact commonplace.