Final answer:
ATP acts as the energy currency of the cell due to its high-energy phosphate bonds, especially between the second and third phosphate groups, which release energy when hydrolyzed.
Step-by-step explanation:
The structure of adenosine triphosphate (ATP) allows it to act as the cell's primary energy currency due to the high-energy bonds between its phosphate groups. ATP is composed of a ribose sugar, an adenine base, and three phosphate groups. The bond between the second and third phosphate groups is particularly high-energy. When ATP undergoes hydrolysis, this bond is broken, releasing a significant amount of energy (approximately 7.3 kilocalories per mole) which is then used to fuel various cellular activities such as muscle contraction, transport of substances in and out of cells, and anabolic chemical reactions.
In contrast, the bonds connecting the ribose, adenine, and the first phosphate group do not store as much energy and are less involved in the energy-transfer processes. Thus, the characteristic of ATP that allows it to act as an energy currency is the high-energy phosphate bonds, particularly those between the second and third phosphate groups.