What is the Difference Between Trypsin and Pepsin?

Trypsin and pepsin are both proteolytic enzymes involved in the digestion process, but they have some key differences:

1. Origin and Secretion: Pepsin is secreted by the gastric juice in the stomach, while trypsin is secreted by the pancreatic juice in the small intestine.
2. Optimal pH: Pepsin acts in an acidic environment (pH 1.8), while trypsin acts in an alkaline environment (pH 7.5-8).
3. Activation: The inactive form of pepsin, pepsinogen, is activated by the hydrochloric acid (HCl) of the gastric juice. In contrast, the inactive form of trypsin, trypsinogen, is activated by an enzyme called enterokinase.
4. Catalysis Mechanism: Pepsin is an aspartic protease that uses a catalytic aspartate in its active site, while trypsin is a serine protease employing the serine residue in its active site.
5. Function: Pepsin acts on proteins and converts them into peptones, while trypsin converts peptones into polypeptides.
6. Types: Pepsin has four different types: A, B, C, and D. Trypsin has two types: α-trypsin and β-trypsin.

In summary, pepsin and trypsin are both involved in breaking down proteins in the digestive system, but they function in different environments (acidic vs. alkaline) and have distinct activation mechanisms, functions, and types.

Comparative Table: Trypsin vs Pepsin

Here is a table comparing the differences between trypsin and pepsin:

Both trypsin and pepsin are proteolytic enzymes that act on proteins and break them down into peptides and amino acids. However, they have different origins, catalysis mechanisms, optimal pH, types, and specificities.