What are the major digestive enzymes produced by the pancreas and their substrates?

• A. Amylase (carbohydrates), Lipase (fats), Nucleases (nucleic acids)
• B. Nucleases only
• C. Amylase only
• D. Amylase (carbohydrates), Lipase (fats), Proteases such as trypsin, chymotrypsin, and carboxypeptidase (proteins); nucleases also present

Answer: (D)

Think about what the pancreas does best: supply enzymes that tackle the four major types of dietary macromolecules. The pancreas releases enzymes into the small intestine that are matched to those targets.

Pancreatic amylase handles carbohydrates, especially starch, breaking it down into smaller sugars. Pancreatic lipase digests fats (triglycerides), producing fatty acids and monoglycerides. Proteases such as trypsin, chymotrypsin, and carboxypeptidase chew up proteins, cutting peptide bonds to form peptides and amino acids. Nucleases present in pancreatic juice break down nucleic acids (DNA and RNA) into nucleotides. It’s also useful to note that these proteases are secreted as inactive precursors and activated in the intestine to prevent damage to the pancreas itself.

That combination—amylase for carbohydrates, lipase for fats, proteases for proteins, and nucleases for nucleic acids—covers the major pancreatic enzymes and their substrates, which is why this option is the best fit. The other choices omit one or more of these key enzyme groups, making them incomplete.