What is the primary energy carrier molecule in cells?

Adenosine triphosphate (ATP) is recognized as the primary energy carrier molecule in cells because it plays a central role in storing and transferring energy within cells. ATP consists of adenine, ribose, and three phosphate groups. The energy stored in ATP is released when one of the phosphate bonds is broken, resulting in adenosine diphosphate (ADP) and an inorganic phosphate. This energy release is crucial for various cellular processes, including muscle contractions, active transport across membranes, and the synthesis of macromolecules.

Furthermore, ATP is generated through cellular respiration and photosynthesis, making it accessible for driving the chemical reactions necessary for life. Other molecules, like NADH and GTP, have important roles in metabolic pathways and signaling, but they do not serve as the primary energy currency in the same way ATP does.