The duodenum does not produce its own enzymes. The three major enzymes involved in digestion that are *active* in the duodenum are produced by the pancreas:

1. Pancreatic amylase: Breaks down carbohydrates (starch) into simpler sugars.

2. Pancreatic lipase: Breaks down fats (lipids) into fatty acids and glycerol.

3. Trypsin (and other proteases): Breaks down proteins into amino acids.

While the duodenum itself doesn't produce these enzymes, it plays a crucial role in digestion by providing the optimal environment for these enzymes to work.