The enzyme used in the hydrolysis of starch to dextrin and maltose is?

Step 1: Analyze the question The question asks which enzyme breaks down starch (a polysaccharide) into dextrin and maltose.

Step 2: Explain the concept Enzymes are biological catalysts, and each one acts on a specific substrate. The name of an enzyme often hints at its substrate.

| Enzyme | Substrate | Product | |---|---|---| | Amylase (diastase) | Starch | Dextrin and maltose | | Maltase | Maltose | Glucose | | Lipase | Fats and oils | Fatty acids and glycerol | | Invertase (sucrase) | Sucrose | Glucose and fructose | | Zymase | Glucose (fermentation) | Ethanol and carbon dioxide |

Step 3: Work through the options

• A. Lipase: acts on fats and oils, not starch. ❌
• B. Amylase: the "amyl-" part comes from amylum, meaning starch. It hydrolyses starch to dextrin and maltose. ✅ (Salivary amylase, also called ptyalin, starts this process in the mouth.)
• C. Invertase: converts sucrose to glucose and fructose (invert sugar). ❌
• D. Zymase: found in yeast, it converts glucose to ethanol and CO₂ during fermentation. ❌

Step 4: Answer The correct option is B. amylase.

Step 5: Exam tip Match the enzyme to its substrate using the name:

• Amylase → Amylum (starch)
• Lipase → Lipids (fats)
• Maltase → Maltose
• Zymase → fermentation of glucose (yeast)

Also remember the full pathway: starch → (amylase) → dextrin and maltose → (maltase) → glucose.