Complex sentence: Adenosine triphosphate (ATP) is a nucleoside triphosphate, a small molecule used in cells as a coenzyme often called the "molecular unit of currency" of intracellular energy transfer.
Split into simpler sentences: Adenosine triphosphate (ATP) is a nucleoside triphosphate, a small molecule used in cells as a coenzyme. It is often referred to as the "molecular unit of currency" of intracellular energy transfer.