Final answer:
ATP is favored when energy is abundant, while glycogen is used to make ATP when energy is scarce.
Step-by-step explanation:
ATP is favored when energy is abundant because it is readily available and provides a consistent amount of energy. On the other hand, glycogen is used to make ATP when energy is scarce. When there is excess ATP and glucose, the liver converts them into glycogen, which can be stored and later used to produce energy when food is scarce.