Science glossary film: Digestion

The mechanical and chemical breakdown of food in the body into simpler chemicals that can be absorbed and used in its metabolism. In vertebrates, the process starts with chewing and the action of saliva in the mouth, and continues down the alimentary canal by the action of further digestive enzymes. Some single-celled organisms, on the other hand, simply engulf a meal to digest it.

In vertebrates, the process starts with chewing and the action of saliva in the mouth, and continues down the alimentary canal by the action of further digestive enzymes. Some single-celled organisms, on the other hand, simply engulf a meal to digest it.