Answer:
ATP: Glucose provides energy to reform ATP. ATP then use this energy to do all type of movements and reactions. The ATP molecules provide energy immediately that helps the functions of the cell. Its function is to supply energy for transport, movement, & protein synthesis.
Fat: these molecules provide long-term energy storage. It can be released by chemical reactions. This energy can be used to reform ATP molecules as glucose reforms but different chemical reactions, which can be used to provide.
Thus, ATP is immediate source of energy while fat provide long term energy storage.