Batteries, biomass, petroleum, natural gas, and coal are examples of stored chemical energy
In the stomach, food undergoes chemical and mechanical digestion. Peristaltic contractions (mechanical digestion) churn the bolus, which mixes with strong digestive juices that the stomach lining cells secrete (chemical digestion). As food travels from your mouth into your digestive system, it's broken down by digestive enzymes that turn it into smaller nutrients that your body can easily absorb. This breakdown is known as chemical digestion.
