Digestion as an example of integrated teaching of chemistry and biology

Most people are uncertain about how nutrients enter and are distributed in the body. They may be capable of naming the different parts of the digestive system on a torso but have vague ideas of the relation between these organs and the chemical processes they govern. Reasons for this are poor understanding of gas exchange, the role of the circulatory system, and that most processes are intracellular. In order to create a more holistic view of the biology and chemistry of digestion these subjects may be taught simultaneously and integrated. Here practical exercises and lectures about digestion and nutrients for pre-service primary school teachers are presented. The practical work included food preparation in order to investigate the change of the properties of the macromolecules of nutrients. A simple drawing of a body was used in order to visualize the routes of nutrients and the role of gas exchange in digestion. An evolutionary perspective on digestion was used in order to explain the ancient origin of most chemical processes in the digestive system and in the whole body. The material produced by the students at their final examinations was used for assessing their use and understanding of concepts, the quality based on Doll’s 4R’s and the degree of holistic understanding of the digestive system. The findings show that the pedagogic design used gives a general picture of digestion and energy transfer usable for teaching in primary school.