Question

If enzyme code EC 2.6.1.1 belongs to aspartate amino transferase, then the code EC 4.3.1.3 belongs to which enzyme?

(a) Chymosin

(b) Histidase

(c) Glucose oxidase

(d) Glutathione synthetatase

I had been asked this question during an interview.

The question is from Enzyme Kinetics Fundamentals topic in chapter Enzyme Kinetics Fundamentals of Enzyme Technology

Answer 1

Correct answer is (b) Histidase

To explain: Enzyme commission by International Union of Biochemistry assigned each enzyme a recommended name and a 4 digit code. Code 4.3.1.3 belongs to histidase which is an example for lyase class of enzymes. The first digit codes for the main class of enzymes. The second digit codes for the type of enzyme catalyzed reaction whereas the third digit describes the enzyme catalyzed reaction. The fourth digit gives a number which keeps on changing as new enzymes are discovered.