Question

Match each phrase with the appropriate part of the digestive system. You may use each answer once, more than once, or not at all. Contains endocrine and exocrine cells Digestion of proteins begins her

Answer 1

Protein digestion starts in the stomach with HCl and pepsin breaking down proteins into polypeptides and continues in the small intestine with pancreatic enzymes reducing them to amino acids.

Step-by-step explanation:

The digestion of proteins begins in the stomach, where hydrochloric acid (HCl) and the enzyme pepsin start the process of breaking down proteins into smaller polypeptides. This initial stage prepares proteins to be further digested and absorbed in the small intestine.

There, pancreatic enzymes such as trypsin and chymotrypsin, which are secreted by exocrine cells, continue the chemical digestion by breaking down these polypeptides into amino acids. Additionally, hormones secreted by endocrine cells, like secretin and cholecystokinin (CCK), aid the digestive process.

To answer the student's question directly, digestion of proteins begins in the stomach (B), and the correct answer choice for the multiple-choice part is stomach; pepsin; HCl; amino acids (d), as amylase is involved in carbohydrate digestion, not protein.