Answer:
ATP is used for immediate energy and short-term storage, while starch molecules are stable and can be stored for a long time.
Step-by-step explanation:
ATP acts as an immediate energy source because it only requires a single step to be converted into energy. Starch molecules have to under go series of steps to be converted into energy hence they act as energy reservoirs for the cells. Starch is used by the plants for storing of glucose. this glucose is then use as an energy source. Hence, ATP serves as an immediate but short- term energy storage molecule whereas starch serves as a long time energy storage molecule.