The end products of protein digestion are

A

monosaccharides

B

steroids

C

amino acids

D

fatty acids

Amino acids and proteins are the building blocks of life. Amino acids are organic compounds that combine to form proteins.
When proteins are digested or broken down, amino acids are left. Zymogenic cell or peptic cell in the stomach that releases pepsinogen and chymosin.
This inactive pepsinogen, on exposure to hydrochloric acid, gets converted to the active enzyme pepsin.
Pepsin is produced in the stomach and is one of the main digestive enzymes, which helps in digestion of the proteins to polypeptide chains. The end product of protein is it mustbe broken down into amino acids. Hence, the end product of protein digestion is amino acids.So, the correct answer is 'amino acids'.