Understand that ATP (adenosine triphosphate) is a nucleotide composed of three main components: a nitrogenous base, a sugar, and phosphate groups.
Identify the nitrogenous base in ATP, which is adenine, a purine base important for energy transfer.
Recognize the sugar component in ATP is ribose, a five-carbon sugar with hydroxyl groups, distinguishing it from deoxyribose found in DNA.
Note that ATP contains three phosphate groups linked in a chain, which are key to its role in storing and transferring energy.
Combine these components to describe ATP as consisting of adenine (base), ribose (sugar), and three phosphate groups, differentiating it from options with sulfate groups or other bases like guanine.