Question

Ammonia or ammonium is oxidized to nitrite followed by the oxidation of nitrite to nitrate is called ____________

(a) Nitrogen fixation

(b) Nitrification

(c) Denitrification

(d) Nitrogen assimilation

This question was addressed to me in a job interview.

My query is from Overview of Nitrogen Metabolism topic in portion Lipid Biosynthesis, Biosynthesis of Amino Acids, Nucleotides and Related Molecules of Biochemistry

Answer 1

Correct option is (b) Nitrification

Explanation: Nitrate is reduced and ultimately produces N2 through a series of intermediate gaseous nitrogen oxide products is called denitrification.

Conversion of nitrogen to ammonia or nitrogenous compounds is termed as nitrogen fixation.

Formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds is called nitrogen assimilation.