What is the role of lingual lipase, and where is it active?

• A. Lipid digestion; active in the mouth and stomach; secreted by lingual glands
• B. Protein digestion; active in the stomach
• C. Carbohydrate digestion; active in the small intestine
• D. Lipid digestion; secreted by pancreas

Answer: (A)

Lingual lipase is an enzyme that starts lipid digestion. It is produced by the lingual glands on the tongue and secreted with saliva. It can act in the mouth, helping to begin breaking down fats even before they reach the stomach, and it remains active in the acidic stomach environment where it contributes further to fat digestion alongside gastric lipase. This combination—lipid digestion, activity in both the mouth and stomach, and secretion by lingual glands—fits the best. The other options misstate the substrate (proteins or carbohydrates) or the source of secretion (pancreas) and overlook that its activity spans the mouth and stomach.