Adenosine triphosphate (ATP) is primarily known as the energy currency of the cell. It plays a critical role in intracellular energy transfer, providing the energy required for various biological processes such as muscle contraction, nerve impulse propagation, and chemical synthesis. In metabolic pathways, ATP is generated during cellular respiration and photosynthesis and is consumed in processes that require energy input, including active transport across cell membranes and biosynthesis of proteins and nucleic acids.

In medicine, ATP is used in diagnostic procedures, particularly in stress testing for heart conditions, where it helps evaluate coronary artery function by inducing controlled changes in heart rate and blood flow. It is also utilized in some intravenous formulations to treat certain cardiac arrhythmias, especially supraventricular tachycardia, due to its ability to transiently block electrical conduction in the atrioventricular node.

In research and biotechnology, ATP is essential in assays that measure cell viability, as its presence indicates metabolically active cells. It is also used in enzymatic reactions, such as those involving kinases, and in molecular biology techniques like luciferase-based bioluminescence detection, where ATP levels correlate with microbial contamination or cellular activity.