What initiates the breakdown of carbohydrates in the digestive system?

The breakdown of carbohydrates in the digestive system begins in the mouth, where the enzyme amylase, found in saliva, initiates the process of digestion. This enzyme specifically targets starches, converting them into simpler sugars such as maltose. As food is chewed and mixed with saliva, the amylase acts on the carbohydrates present, breaking them down before the food even reaches the stomach.

In contrast, pepsin is primarily responsible for the digestion of proteins and is active in the acidic environment of the stomach, where it does not play a role in carbohydrate digestion. Hydrochloric acid in the stomach helps create an optimal environment for pepsin but does not directly participate in breaking down carbohydrates. Lipase is an enzyme that aids in the digestion of fats in the duodenum and does not target carbohydrates. Therefore, saliva in the mouth is the correct answer, as it is the starting point for carbohydrate digestion in the digestive process.