Question

Which of the following enzymes converts proteins into peptones?

• A. Trypsin
• B. Pepsin
• C. Erepsin
• D. Enterokinase

Hint:

Pepsin acts in the stomach and initiates protein digestion. Remember: Protein $\rightarrow$ Peptones by Pepsin.

Answer 1

The Correct Option is B

Concept: Digestion of proteins is a complex biochemical process that involves several enzymes acting at different stages in the digestive system. Proteins are large macromolecules composed of amino acids linked together by peptide bonds. Since proteins are too large to be absorbed directly by the body, they must first be broken down into simpler substances. Various enzymes such as pepsin, trypsin, and erepsin participate in this process.

Step 1: Understand the role of pepsin. Pepsin is one of the earliest protein-digesting enzymes that acts in the stomach. It is secreted in an inactive form called pepsinogen by gastric glands. Hydrochloric acid (HCl) present in the stomach converts pepsinogen into active pepsin.

Step 2: Examine the action of pepsin on proteins. Pepsin begins the digestion of proteins by breaking them into smaller molecules known as proteoses and peptones. Thus, pepsin plays a major role in converting complex proteins into peptones.

Step 3: Analyze the remaining options. Trypsin acts mainly in the small intestine and further digests proteins and peptides. Erepsin converts peptides into amino acids. Enterokinase activates trypsinogen into trypsin and does not directly digest proteins.

Step 4: Identify the correct answer. Since pepsin is the enzyme responsible for converting proteins into peptones, it is the correct choice. Hence, option (B) is correct.