Question

Which enzyme is involved in biological nitrogen fixation?

Answer 1

Beijerinck discovered the process of biological nitrogen fixation (BNF) in $1901$ and identified the prokaryotes that carry out the process. These organisms employ the nitrogenase enzyme to catalyse the conversion of atmospheric nitrogen to a form of nitrogen called ammonia ($N{H_3}$).

Complete answer:
The enzyme involved is nitrogenase.
Prokaryotes include the enzyme nitrogenase, which can fix nitrogen in higher plants. It is made up of a cofactor and two components that make up the nitrogen fixing site. A component of chlorophyll is one of the elements.
Nitrogen fixation is a biological process that converts nitrogen gas into a form that plants and other microorganisms can use. Nitrogen gas in the atmosphere is transformed into ammonia and other nitrogenous chemicals in this process.
Types of nitrogen fixation:
1. Physical Nitrogen Fixation - Physical nitrogen fixation accounts for about $10\%$ of nitrogen fixation. Lightning is an example of a physical process in which a di-nitrogen molecule combines with oxygen to produce nitric oxide. $N{O_2}$ is formed when this is oxidised. It produces nitrous and nitric acid, which is incorporated into the soil with the rain.
2. Biological Nitrogen Fixing - Biological mechanisms account for almost $90\%$ of nitrogen fixation examples. The conversion is carried out here with the assistance of a few live creatures.
The process of turning atmospheric nitrogen into nitrogenous compounds produced by living organisms is known as symbiotic nitrogen fixation.

Note:
The process of converting ammonium salts into nitrates and nitrites into nitrates is known as nitrification. Because of the action of nitrifying bacteria, irrigation with weak ammonia solutions causes soil nitrates to rise in agriculture. Nitrifying bacteria convert ammonia, the simplest form of nitrogen in soil, to nitrate, the most oxidised form. It happens in two stages: nitrite formation and nitrate formation, for example.