Final answer:
The three amino acids in the catalytic triad of prothrombin are histidine, serine, and aspartic acid. These residues are essential for the enzyme's function in blood clotting. The option (B) is correct.
Step-by-step explanation:
The three amino acids found in the catalytic triad of prothrombin are histidine, serine, and aspartic acid. These amino acids are crucial for the enzyme's ability to catalyze the conversion of prothrombin to thrombin, a key step in the blood clotting process. Prothrombin is a protein that plays a significant role in blood coagulation and is activated by a catalytic triad that usually consists of specific amino acids capable of accelerating the conversion process through their chemical properties.
Experimentally, it has been observed that active sites often comprise a small portion of the enzyme, within which certain amino acids with functional groups like histidine, cysteine, aspartic acid, arginine, and glutamic acid catalyze reactions owing to their ability to participate in acid-base or electrophile-nucleophile catalysis. The correct combination of amino acids in the catalytic triad of prothrombin is histidine, serine, and aspartic acid. Therefore, option (B) is correct.