Question

For its action, nitrogenase requires
A. High input of energy
B. Light
C. Mn⁽²⁺⁾
D. Super Oxygen radicals

Answer 1

Hint: The biological nitrogen fixation includes the key enzyme nitrogenase. The conversion of nitrogen to ammonia can be done with the help of the nitrogenase enzyme. It is the bacterial enzyme that catalyzes the ATP-dependent reduction of dinitrogen (N₂) to ammonia (NH₃). Molybdenum aids in nitrogen fixation.

Complete step by step solution:
The nitrogenase enzyme is present in prokaryotic nitrogen fixers. Each mole of nitrogen is reduced with the help of microbes that need 16 moles of ATP to fix nitrogen. A large amount of energy is required for the conversion of N₂ to NH₃ by the enzyme nitrogenase. The nitrogenase enzyme gets activated by vanadium.

Manganese is an essential element for the process of nitrogen fixation. It also helps in conversion but not inactivation.

Light helps in the breakdown of nitrogen molecules and also allows them to combine with oxygen but does not play important role in the action of nitrogenase.

Oxygen radicals include superoxide anion radical, per hydroxyl radical, etc. These are unstable molecules that contain oxygen and that easily react with other molecules.

High input of energy is required by the Nitrogenase enzyme to carry out biological nitrogen fixation. It requires high energy because microorganisms need it to for oxidizing organic molecules.

Hence, Option A is the correct answer.

Note: Bulen and LeComte discovered Nitrogenase. It is inhibited by oxygen. Below oxygen threshold concentration, nitrogenase remains active and above which nitrogen fixation stops completely. Two components and complex metalloenzymes catalyze the biological nitrogen fixation.