Summary
Highlights
Digestive enzymes are crucial for breaking down large, insoluble food molecules into smaller, soluble ones that can be absorbed into the bloodstream. There are three primary types: carbohydrases, lipases, and proteases, each targeting a specific type of nutrient.
Carbohydrases break down carbohydrates into smaller sugar molecules. They are produced in the salivary glands, pancreas, and the epithelial cells lining the ileum. The digestion of starch begins in the mouth with salivary amylase, continues in the small intestine with pancreatic amylase, and concludes with membrane-bound disaccharidases like maltase, sucrase, and lactase, which break down disaccharides into monosaccharides like glucose, fructose, and galactose for absorption.
Lipases break down lipids (fats and oils) into fatty acids and monoglycerides. They are primarily produced by the pancreas. Before lipase action, bile salts produced by the liver emulsify large lipid droplets into smaller micelles, increasing the surface area for lipase activity and accelerating lipid breakdown and subsequent absorption by the body.
Proteases (also called peptidases) break down proteins first into smaller peptides and then into individual amino acids. These enzymes are produced in the stomach, pancreas, and the epithelial cells lining the ileum. Endopeptidases break internal peptide bonds, exopeptidases remove amino acids from the ends of polypeptides, and dipeptidases break dipeptides into single amino acids, which are then absorbed into the bloodstream.