Intestinal juice contains the following enzymes EXCEPT

Analyze the question: We need the enzyme that is NOT found in intestinal juice (succus entericus), which is secreted by glands in the wall of the small intestine.

Concept: Different digestive juices contain different enzymes:

• Intestinal juice (succus entericus) contains: • Erepsin (peptidases that break peptides into amino acids) • Maltase (maltose → glucose) • Sucrase (sucrose → glucose + fructose) • Lactase (lactose → glucose + galactose) • Intestinal lipase (fats → fatty acids and glycerol)
• Pancreatic juice contains trypsin, pancreatic amylase and pancreatic lipase.

Step by step:

• A. Erepsin: present in intestinal juice. ✔
• B. Lipase: a small amount of lipase is present in intestinal juice. ✔
• C. Maltase: present. ✔
• D. Sucrase: present. ✔
• E. Trypsin: it is made by the pancreas as inactive trypsinogen and is released into the duodenum in pancreatic juice. It is activated there by enterokinase, an enzyme of the intestinal juice. So trypsin is not itself a secretion of the intestinal glands. ✘

Answer: E. trypsin

Tip: Remember "trypsin = pancreas". The intestinal juice contains the enzymes that finish digestion: erepsin, maltase, sucrase and lactase. The intestinal juice only supplies enterokinase, which activates the trypsin that comes from the pancreas.