Chemical digestion

What the syllabus asks of you

• Describe chemical digestion as the breakdown of large insoluble molecules into small soluble molecules
• State the role of chemical digestion in producing small soluble molecules that can be absorbed
• Describe the functions of enzymes as follows: 6 Describe the digestion of starch in the digestive (a) amylase breaks down starch to simple system: reducing sugars (a) amylase breaks down starch to maltose (b) proteases break down protein to amino (b) maltase breaks down maltose to glucose acids on the membranes of the epithelium lining (c) lipase breaks down fats and oils to fatty the small intestine acids and glycerol
• State where, in the digestive system, amylase, 7 Describe the digestion of protein by proteases protease and lipase are secreted and where in the digestive system: they act (a) pepsin breaks down protein in the acidic
• Describe the functions of hydrochloric acid conditions of the stomach in gastric juice, limited to killing harmful (b) trypsin breaks down protein in the alkaline microorganisms in food and providing an acidic conditions of the small intestine pH for optimum enzyme activity 8 Explain that bile is an alkaline mixture that neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action