Where is the protease pepsin primarily active and what substrate does it act upon?

• A. Pepsin is primarily active in the stomach and acts on proteins, breaking them into smaller peptides
• B. Pepsin is a brush-border enzyme in the small intestine that converts monosaccharides into polysaccharides
• C. Pepsin is primarily active in the mouth and acts on carbohydrates to produce glucose
• D. Pepsin is secreted by the pancreas and primarily digests triglycerides into fatty acids

Answer: (A)