2003 AIPMT Mineral NutritionNitrogen Fixation: Nitrogenase Easy Question 53 of 63 in Mineral Nutrition

Which one of the following mineral elements plays an important role in biological nitrogen fixation : -

A Copper
B Manganese
C Zinc
D Molybdenum

The answer is D.

Solution

Biological nitrogen fixation is catalysed by the enzyme nitrogenase, which reduces $N_2$ to $NH_3$.
Nitrogenase is a Mo–Fe protein: molybdenum and iron are essential components of its active site.
Molybdenum is also a component of nitrate reductase, needed for nitrogen assimilation.
So molybdenum plays an important role in biological nitrogen fixation (Mo deficiency reduces nodule activity in legumes).

Concept Molybdenum in nitrogenase

Mineral Nutrition in past papers

63 questions from this chapter have appeared across 23 exam years.