The chemical digestion also occurs on the small intestine. The small intestine is made up of the duodenum, jejunum and ileum; these parts are essential for two main roles which is the breaking down of macromolecules and absorption of water and nutrients. According to (Guerra A. et al., 2012) Pancreatic enzymes and other digestive enzymes produced by the inner wall of the small intestine act together in the breakdown of food constituents.