Q: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
It is used in pain sensitization as a signaling molecule that binds to purinergic receptors. It is also potent inhibitor of both pyruvate kinase and phosphofructokinase. In muscle cells it is often indirectly transported throughout the cell via creatine, which can accept or donate a phosphate group and form this organic molecule. The enzyme adenylate cyclase converts it into the second messenger cyclic AMP, but this molecule is most famously associated with the metabolic processes of photosynthesis, glycolysis, and oxidative phosphorylation. FTP, name this nucleotide used by most cells as the "energy currency. "
A:
Science