Question

Conversion of nitrogen to ammonia or nitrogenous compounds is termed as ____________

(a) Nitrogen fixation

(b) Nitrification

(c) Denitrification

(d) Nitrogen assimilation

The question was asked during an interview.

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

Answer 1

Correct choice is (a) Nitrogen fixation

For explanation: Formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds is called as nitrogen assimilation.

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

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