Which type of substrate is digested (hydrolyzed) by the enzyme protease?

• A. Triglycerides (fats)
• B. Proteins (polypeptides)
• C. Starch and other polysaccharides
• D. DNA and RNA (nucleic acids)

Answer: (B)

Verified step by step guidance

1. Understand that proteases are enzymes that catalyze the hydrolysis of peptide bonds in proteins, breaking them down into smaller peptides or amino acids.
2. Recall the four main types of biological macromolecules: proteins (polypeptides), lipids (such as triglycerides), carbohydrates (such as starch), and nucleic acids (DNA and RNA).
3. Identify that triglycerides are broken down by lipases, starch and polysaccharides by amylases, and nucleic acids by nucleases, not proteases.
4. Recognize that since proteases specifically target peptide bonds, their substrate must be proteins or polypeptides.
5. Conclude that the substrate digested by protease is proteins (polypeptides), as they contain the peptide bonds that proteases hydrolyze.