Chewing food breaks down the food slightly making it even easier for the food to be broken down further in the stomach. Chewing has little affect on releasing chemical energy in food, but, it helps the food travel down the esophagus. Imagine eating an apple without chewing!!!

It works through a chemical reaction between the acid in the lemon juice and the two electrodes ( two examples are magnesium and copper) This reaction causes electrons to flow through the circuit. However not much power is produced. Other citric fruits such as Oranges, limes and grapefruits work just as well.