Which statement best describes the breakdown of food in the digestive system?

Carbohydrate digestion starts in the stomach and protein digestion starts in the stomach.

Carbohydrate digestion starts in the mouth and protein digestion starts in the stomach.

Carbohydrate digestion starts in the esophagus and protein digestion starts in the small intestine.

Carbohydrate digestion starts in the small intestine and protein digestion starts in the esophagus.

Answer: The second option.

Carbohydrate digestion starts in the mouth and protein digestion starts in the stomach.

Carbohydrate digestion starts in the mouth by the mechanical activity of chewing and saliva from the salivary amylase, an enzyme in the salivary glands.

Protein digestion occurs in the stomach where three main enzymes, pepsin secreted by the stomach, and trypsin and chymotrypsin secreted by the pancreas. The enzymes would break down the food proteins into polypeptides and into smaller and smaller pieces until they are amino acids.

Answer: The correct answer is option B: Carbohydrate digestion starts in the mouth and protein digestion starts in the stomach.