How does structure and functions of the digestive system contribute to the processing and storage of energy in the body.

Digestive system is responsible for the digestion of food materials. In digestive system, food material such as protein, carbohydrates and fats are converted into amino acid, glucose and faty acid respectively. Our body absorbed nutrients in the form of glucose, amino acid and fatty acid. Digestive system uses amino acid for the repair and formation of muscle. Body needs energy for performing different functions and extra energy is stored in the form of glycogen and use when it is needed.