Digestive Enzymes

Salivary amylase

Secreted by the salivary glands;

begins carbohydrate digestion by breaking starch into smaller sugars, including maltose

Lingual lipase

• Secreted by glands of the tongue;

• begins triglyceride digestion and becomes most active in the acidic stomach

Pepsin

Secreted by gastric glands as inactive pepsinogen; breaks proteins into smaller peptides in the stomach

Gastric lipase

Secreted by the stomach; digests a small amount of triglycerides into fatty acids and diglycerides

Pancreatic amylase

Secreted by the pancreas into the small intestine; breaks starch into maltose and short carbohydrate chains

Pancreatic lipase

Secreted by the pancreas into the small intestine; breaks triglycerides into monoglycerides and free fatty acids

Trypsin

Secreted by the pancreas as inactive trypsinogen; breaks proteins and polypeptides into smaller peptides in the small intestine

Chymotrypsin

Secreted by the pancreas as inactive chymotrypsinogen; breaks proteins and polypeptides into smaller peptides

Elastase

Secreted by the pancreas as inactive proelastase; digests elastin and other proteins into smaller peptides

Carboxypeptidase

Secreted by the pancreas as an inactive proenzyme; removes amino acids from the carboxyl end of peptides

Enteropeptidase

Produced by the small-intestinal lining; activates trypsinogen by converting it into trypsin

Aminopeptidase

Located on the small intestine's brush border; removes amino acids from the amino end of peptides

Dipeptidase

Located on the small intestine's brush border and inside intestinal cells; splits dipeptides into individual amino acids

Maltase

Located on the small intestine's brush border; breaks maltose into two glucose molecules

Sucrase

Located on the small intestine's brush border; breaks sucrose into glucose and fructose

Lactase

Located on the small intestine's brush border; breaks lactose into glucose and galactose

Alpha-dextrinase

Located on the small intestine's brush border; breaks branched dextrins produced during starch digestion into glucose

Deoxyribonuclease (DNase)

Secreted by the pancreas into the small intestine; breaks DNA into nucleotides

Ribonuclease (RNase)

Secreted by the pancreas into the small intestine; breaks RNA into nucleotides

Nucleosidase

Located on the small intestine's brush border; breaks nucleosides into nitrogenous bases and pentose sugars

Phosphatase

Located on the small intestine's brush border; removes phosphate groups from nucleotides

Phospholipase

Secreted by the pancreas; breaks phospholipids into fatty acids and other smaller components

Cholesterol esterase

Secreted by the pancreas; breaks cholesterol esters into cholesterol and free fatty acids