Final answer:
While both serine proteases and aspartic proteases are involved in breaking down proteins, serine proteases have a serine residue at their active site and participate in various physiological processes, whereas aspartic proteases contain aspartic acid residues and are primarily involved in protein digestion in acidic environments.
Step-by-step explanation:
Serine proteases and aspartic proteases are both classes of proteolytic enzymes, which play crucial roles in various biological processes. Although they share a general function in breaking down proteins, they have distinct active site compositions and mechanisms of action. Serine proteases contain a serine residue at their active site, which participates in catalysis, and they are often involved in diverse physiological processes such as digestion and blood coagulation.
These enzymes are commonly activated through the cleavage of a specific peptide bond within their structure. Well-known serine proteases include trypsin, which targets basic amino acids like lysine and arginine, and chymotrypsin, which prefers aromatic amino acids. On the other hand, aspartic proteases have two aspartic acid residues at their active site and are well-known for their role in protein digestion, particularly under acidic conditions.
Pepsin is an example of an aspartic protease that cleaves peptide bonds involving aromatic amino acids like phenylalanine, tyrosine, and tryptophan. Aspartic proteases are activated by the acidification of their environment, as seen in the stomach during digestion.