What is the final product of protein digestion in the small intestine?

The final product of protein digestion in the small intestine is amino acids. This process begins in the stomach, where enzymes such as pepsin start breaking proteins down into smaller polypeptides. As the partially digested proteins enter the small intestine, further enzymatic action occurs, primarily through pancreatic enzymes like trypsin, chymotrypsin, and carboxypeptidase. These enzymes continue to break down polypeptides into even smaller units, ultimately resulting in amino acids.

Amino acids are the fundamental building blocks of proteins and are crucial for various physiological functions in the body, including tissue repair, hormone production, and the synthesis of neurotransmitters. Once proteins are digested into amino acids, they can be absorbed through the walls of the small intestine into the bloodstream and transported to cells where they are utilized for various metabolic processes.

In contrast, polypeptides, while present during the digestion process, are not the final form of protein digestion. Fibers and sugars are unrelated to protein digestion as fibers pertain to carbohydrates and sugars are produced from carbohydrate digestion. Thus, understanding that amino acids serve as the end products of protein digestion clarifies their importance in nutrition and bodily functions.