Nitrogenase is a critical enzyme in the nitrogen cycle because it catalyzes the
A) assimilation of ammonia.
B) dissimilative reduction of nitrate to nitrogen gas.
C) fixation of nitrogen gas into ammonia.
D) oxidation of nitrogen gas into nitrate.

Question

Quizplus · Accepted Answer

Nitrogenase is responsible for fixing atmospheric nitrogen gas (N2) into ammonia (NH3). This process is known as nitrogen fixation and is a critical step in the nitrogen cycle. The other options (assimilation of ammonia, dissimilative reduction of nitrate to nitrogen gas, and oxidation of nitrogen gas into nitrate) are all important processes in the nitrogen cycle but are not directly catalyzed by nitrogenase.

Nitrogenase Is a Critical Enzyme in the Nitrogen Cycle Because