. The function of leghaemoglobin during biological nitrogen fixation in root nodules of legumes, is to

(a)  convert atmospheric N2 to NH3

(b)  convert ammonia to nitrite

(c)  transport oxygen for activity of nitrogenase

(d)  protect nitrogenise from oxygen


Best Answer

Answer: D

Solution : In the nodule, precise O2 level are controlled by the O2 binding protein leghaemoglobin. This red iron containing protein is present in healthy nitrogen fixing nodules of leguminous plants. Legaemoglobin functions as an “oxygen buffer” cycling between the ocidized (Fe+3) and reduced (Fe2+) forms to keep free O2 level within the ovule low. The ratio of leghaemoglobin bound O2 to free O2 in the root nodule is on the order of 10,000 : Nitrogenase enzyme, presents in root nodules mainly takes part in nitrogen fixation process. This enzyme becomes inactive in higher concentration of O2.


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