Which of the following food substances is incorrectly linked to its enzyme?

Step 1: Analyze the question We need to find the food substance that is paired with the wrong enzyme. Three pairs are correct and one is wrong.

Step 2: Recall the concept Each enzyme acts on a specific substrate (the lock-and-key idea):

| Enzyme | Substrate | Product | |---|---|---| | Trypsin | Protein (polypeptides) | Peptides and amino acids | | Pepsin | Protein | Peptides | | Lipase | Fats/oils | Fatty acids and glycerol | | Amylase | Starch | Maltose | | Sucrase (invertase) | Sucrose | Glucose and fructose |

Step 3: Check each option

• A. Protein - trypsin: Correct. Trypsin is a protease secreted by the pancreas.
• B. Fat - lipase: Correct. Lipase breaks fats into fatty acids and glycerol.
• C. Sucrose - pepsin: Incorrect. Pepsin is a protease found in the stomach that digests protein. Sucrose is digested by sucrase.
• D. Starch - amylase: Correct. Salivary and pancreatic amylase digest starch to maltose.

Step 4: Answer The incorrectly linked pair is C. Sucrose - pepsin.

Exam tip: Many enzyme names end in "-ase" and are named after their substrate: lipase for lipids, amylase for amylose/starch, sucrase for sucrose, and protease for protein. Pepsin and trypsin are older names that don't follow this rule, so remember that both act on protein.