Ques. 1AIPMT 2001
Enzyme first used for nitrogen fixation
- nitrogenase
- nitroreductase
- transferase
- transaminase
Answer
(1) nitrogenase
Solution
As per NCERT, the reduction of nitrogen to ammonia by living organisms is called biological nitrogen fixation; the enzyme nitrogenase, present exclusively in prokaryotes, is capable of this reduction.
N2 + 8e- + 8H+ + 16ATP 2NH3 + H2 + 16ADP + 16Pi
Transaminase is used later, to transfer the amino group from glutamic acid to keto acids.
∴ The enzyme first used for nitrogen fixation is nitrogenase.
Answer: (1)