Proteases
Protein digestion starts with pepsin in the stomach, but happens because of pancreatic proteases like trypsin and chymotrypsin. These enzymes are first released into the lumen of the small intestine as inactive proteins –  trypsinogen and chymotrypsinogen –  that must be converted into their active forms in order to digest proteins. Trypsinogen is activated by the enzyme enterokinase, which is embedded in the intestinal mucosa. Trypsin and chymotrypsin digest proteins into smaller peptides, but not into single amino acids. Some of the other proteases from the pancreas, like carboxypeptidase, have that ability. The final digestion of peptides into amino acids is largely the effect of peptidases in small intestinal epithelial cells.

Pancreatic Lipase
The major form of dietary fat is a triglyceride, or neutral lipid. A triglyceride molecule cannot be directly absorbed across the intestinal mucosa. Rather, it must first be broken into a 2-monoglyceride and two free fatty acids by the enzyme pancreatic lipase, which is delivered into the intestine as a part of pancreatic juice. Bile salts produced in the liver must also be present in the intestine for lipase to efficiently digest dietary triglyceride and for the resulting fatty acids and monoglyceride to be absorbed. This means that normal digestion and absorption of dietary fat is dependent on secretions from both the pancreas and liver.

Amylase
The major dietary carbohydrate for many species is starch. Amylase is the enzyme that breaks starch down into maltose. The major source of amylase is pancreatic secretions, although amylase is also present in saliva.