Ezra need glucose and protein from the food he ate and oxygen from the air he breathe, so that he can happily play the basketball.
Step-by-step explanation:
Oxygen molecules from the air he breathe pass through his respiratory system and sent to his cells through a circulatory system. The digestive system of Ezra breaks the starch in the bread and protein in the cheese into necessary glucose and amino acids.
The chemical reaction takes place between glucose and oxygen to generate energy by Ezra's cells. The energy generated by the cell is released, so that Ezra have enough energy to play basketball.