Molecule that stores energy in the body, in brief

ATP

Think of the three-letter "currency" cells use to power nearly every biological process.

This clue asks for a short form of the molecule that cells use to store and transfer energy. "In brief" signals the answer is an abbreviation, and "ATP" (adenosine triphosphate) is the well-known energy currency of the body. It’s a common term in biology, so even if you don’t recall the full name, the letters ATP often come to mind for energy-related clues.