The Process of Digestion
• Digestion is a process in which relatively large, insoluble biological
molecules in food (such as starch, proteins) are hydrolysed into
smaller, soluble molecules that can be absorbed across the cell
membranes into the bloodstream and delivered to cells in the body
• Enzymes are essential for the process of digestion as they catalyse the
hydrolysis
• These small soluble molecules (such as glucose and amino acids) are
used either to provide cells with energy (via respiration) or to build
other molecules for cell growth, repair and function
• Proteins are hydrolysed into amino acids
• Carbohydrates are hydrolysed into simple sugars
• Lipids are hydrolysed into a mixture of glycerol and fatty acids
Human Digestive System
The human digestive system includes the following:
• Glands - the salivary glands and glands in the pancreas produce
digestive juices
• The stomach and small intestine - the sites of digestion
• The liver - produces bile
• Small intestine - the site of absorption
• Large intestine - site of water reabsorption