ISSA Nutritionist Practice Exam

The primary energy currency of the cell is adenosine triphosphate (ATP). It plays a critical role in cellular metabolism, serving as a key molecule that stores and transfers energy within cells. ATP is synthesized in the mitochondria during cellular respiration and is utilized in various metabolic processes, including muscle contraction, protein synthesis, and cellular signaling.

ATP consists of three phosphate groups, and the energy stored in the high-energy bonds between these phosphate groups is released when the cell converts ATP to adenosine diphosphate (ADP) and an inorganic phosphate (Pi). The released energy can then be harnessed to power numerous biochemical reactions necessary for life.

Other options, such as ADP (adenosine diphosphate) and AMP (adenosine monophosphate), are related to ATP but serve different roles. ADP acts as a precursor to ATP and is produced when ATP releases energy. Similarly, AMP is created when ADP loses a phosphate group. UDP (uridine diphosphate) is involved in carbohydrate metabolism and nucleotide synthesis but does not play the primary role of energy currency like ATP does.