Enzymes involved in digesting starch, proteins and fats are listed. The sources of these enzymes are identified on an animated model of a human body. The adaptations of the small intestine are described, including musculature for peristalsis and villi for absorption. The film finishes with an overview of digestion.

First broadcast:
21 November 2008

Discuss with the class the idea that each enzyme has a set of optimum conditions in which it will work best and relate this to their position in the body. Students could create a flow diagram that explains the digestive process and on which they note different stages where food is broken down and the enzymes involved.