Question

First enzyme to be isolated in pure crystalline form was
A. Zymase
B. Urease
C. Invertase
D. Diastase

Answer 1

Hint:
Before we proceed into the problem, it is important to know the definition of crystalline enzymes.
Crystalline enzymes are biocatalysts that have the ability to change chemical compounds into other types of molecules. These enzymes play a major role in many industrial processes, such as making drugs or plastics more effective or less toxic. Some examples of crystalline enzymes include metalloproteinases and glycosidases.

Complete step by step answer:
Eduard Buchner found in 1897 that yeast extracts could ferment sugar into alcohol, demonstrating that chemicals that were released from cells continued to function as catalysts for fermentation. These compounds were classified as enzymes by Frederick W. Kuhne. Early enzyme research made strides after James Sumner isolated and crystallized urease in 1926. Sumner proposed that all enzymes are proteins after seeing that urease crystal were fully made of protein. This concept remained debatable for some time because there weren't any other examples. Only after John Northrop and Moses Kunitz crystallized pepsin, trypsin, and other digestive enzymes and discovered that they, too, were proteins did the general public accept Sumner's findings.
Hydrolysis of urea into ammonia and carbon dioxide is catalyzed. Urease is the enzyme that James Sumner first discovered.
Therefore, the first enzyme to be isolated in pure crystalline form was Urease.

Option ‘B’ is correct

Note:
Urease is an enzyme that helps degrade urinary proteins and other molecules. As a result, it can help to flush waste products out of the system and improve overall bladder health.