Final answer:
The conversion of atmospheric N₂ to biologically useful forms is called nitrogen fixation, a process conducted by microorganisms using the nitrogenase enzyme.
Step-by-step explanation:
The conversion of atmospheric N₂ to biologically useful forms is called nitrogen fixation. This is a critical process in which microorganisms, such as bacteria, convert nitrogen gas from the atmosphere into ammonia (NH₃) or other organic compounds that plants can utilize for growth. The nitrogenase enzyme, which contains iron and molybdenum, is used by these microorganisms to facilitate this conversion. Nitrogen fixation is essential for agriculture as it enables the synthesis of nucleotides and proteins that are crucial for plant development. It is distinct from other processes in the nitrogen cycle, such as nitrification, which converts ammonia into nitrites (NO₂) and nitrates (NO₃), and denitrification, which reduces nitrates back to nitrogen gas, therefore completing the cycle and replenishing the atmosphere.
Nitrogen fixation is the process where organisms convert atmospheric nitrogen into biologically useful chemicals. This process is essential for improving agricultural production as nitrogen is required by plants for nucleotide and protein formation. Some microorganisms, such as rhizobia in the root nodules of legumes, have the ability to fix nitrogen. They employ enzymes called nitrogenases to carry out this conversion.