Which enzyme begins carbohydrate digestion in the mouth?

• A. Pepsin
• B. Salivary amylase
• C. Lactase
• D. Chymotrypsin

Answer: (B)

Salivary amylase is the enzyme responsible for initiating carbohydrate digestion in the mouth. This enzyme is secreted by the salivary glands when food is ingested. It specifically targets starches, breaking them down into simpler sugars like maltose and dextrins.

The pH of the mouth is relatively neutral, making it an ideal environment for salivary amylase to function. Once carbohydrates are mixed with saliva, the digestion process begins immediately, facilitating the breakdown of starches even before they reach the stomach.

The other enzymes listed perform different functions. Pepsin is involved in protein digestion and is active in the acidic environment of the stomach. Lactase is an enzyme that breaks down lactose, the sugar found in milk, primarily working in the small intestine. Chymotrypsin is also a proteolytic enzyme, active in the small intestine, and plays a role in the digestion of proteins rather than carbohydrates. Thus, salivary amylase is specifically tailored for carbohydrate digestion at the very start of the digestive process.