Why digestion is necessary
Why digestion is necessary
Digestion is the breakdown of large, insoluble food molecules into small, soluble molecules. Large molecules such as starch, proteins and lipids are too large to pass through the gut wall.
Step-by-step lessons on AQA GCSE Biology 2.2.1 The human digestive system. Each one builds up to exam-style questions. Start with the foundational topics and build up to the higher-tier material.