Final answer:
In animal cells, energy arrives prepackaged often in the form of ATP (adenosine triphosphate).
Step-by-step explanation:
In animal cells, energy arrives prepackaged often in the form of ATP (adenosine triphosphate). ATP is a high-energy molecule that serves as the primary energy currency of cells. Just like the dollar acts as currency to buy goods, cells use ATP as energy currency to perform immediate work. When needed, the stored chemical energy in ATP can be quickly converted into usable energy by breaking it down into adenosine diphosphate (ADP) and inorganic phosphate (Pi), releasing the stored energy in the process.