Which enzyme is primarily responsible for initiating the digestion of starch in humans?

• A. Lactase
• B. Lipase
• C. Pepsin
• D. Amylase

Answer: (D)

Verified step by step guidance

1. Understand that starch is a polysaccharide composed of glucose units linked by glycosidic bonds, and its digestion requires enzymes that can break these bonds.
2. Recall that lactase is an enzyme that breaks down lactose, a disaccharide sugar found in milk, so it is not involved in starch digestion.
3. Recognize that lipase is an enzyme responsible for breaking down lipids (fats), so it does not act on starch.
4. Know that pepsin is a protease enzyme that digests proteins in the stomach, so it is not involved in carbohydrate digestion.
5. Identify amylase as the enzyme that catalyzes the hydrolysis of starch into smaller sugars, initiating starch digestion primarily in the mouth and continuing in the small intestine.