How is the chemical energy in glucose similar to money in a savings account?
When small molecules come together to form a larger molecule energy is trapped that is saving.
CO2 and H2O comes together during photosynthesis and a glucose molecule is formed. This is like small savings makes sizable amount in your account. During glucose metabolism again glucose is degraded to CO2 and H2O. The trapped energy released from glucose is cashed in terms of ATP. This is spending.