What is the primary function of pepsin in digestion?

What is the primary function of pepsin in digestion?

• A. To neutralize stomach acid
• B. To catalyze the breakdown of proteins
• C. To emulsify fats
• D. To absorb nutrients

Answer: (B)

The primary function of pepsin in digestion is to catalyze the breakdown of proteins. Pepsin is an enzyme that is secreted in its inactive form, pepsinogen, by the gastric glands in the stomach. Once pepsinogen comes into contact with the acidic environment of the stomach, it is activated to pepsin. This active enzyme specifically targets peptide bonds within protein molecules, breaking them down into smaller peptides, which are more easily digestible. Understanding the role of pepsin is fundamental in the context of protein digestion, as proteins are complex macromolecules that require enzymatic cleavage for absorption in the intestines. Following protein breakdown by pepsin, further digestion occurs in the small intestine with the aid of additional enzymes, leading to the absorption of amino acids and small peptides. In contrast, neutralizing stomach acid is primarily the role of bicarbonate ions secreted by the pancreas and does not involve pepsin; emulsifying fats is a function performed by bile salts, not by pepsin; and the absorption of nutrients takes place mainly in the small intestine through various transport mechanisms, rather than being a function of pepsin.

The primary function of pepsin in digestion is to catalyze the breakdown of proteins. Pepsin is an enzyme that is secreted in its inactive form, pepsinogen, by the gastric glands in the stomach. Once pepsinogen comes into contact with the acidic environment of the stomach, it is activated to pepsin. This active enzyme specifically targets peptide bonds within protein molecules, breaking them down into smaller peptides, which are more easily digestible.

Understanding the role of pepsin is fundamental in the context of protein digestion, as proteins are complex macromolecules that require enzymatic cleavage for absorption in the intestines. Following protein breakdown by pepsin, further digestion occurs in the small intestine with the aid of additional enzymes, leading to the absorption of amino acids and small peptides.

In contrast, neutralizing stomach acid is primarily the role of bicarbonate ions secreted by the pancreas and does not involve pepsin; emulsifying fats is a function performed by bile salts, not by pepsin; and the absorption of nutrients takes place mainly in the small intestine through various transport mechanisms, rather than being a function of pepsin.