Label the processes of the nitrogen cycle. <IMAGE>

Verified step by step guidance

1. Identify the key processes involved in the nitrogen cycle: nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.
2. Understand that nitrogen fixation is the conversion of atmospheric nitrogen (N₂) into ammonia (NH₃) or related compounds, primarily by bacteria.
3. Recognize that nitrification is a two-step process where ammonia is first oxidized to nitrite (NO₂⁻) and then to nitrate (NO₃⁻) by nitrifying bacteria.
4. Assimilation involves the uptake of nitrates or ammonia by plants to synthesize organic nitrogen compounds like amino acids.
5. Ammonification is the process of converting organic nitrogen back into ammonia, while denitrification is the reduction of nitrates back into nitrogen gas (N₂), completing the cycle.

Key Concepts

Nitrogen Fixation

Nitrogen fixation is the process by which atmospheric nitrogen (N2) is converted into ammonia (NH3) or related compounds in soil and water. This process is primarily carried out by certain bacteria, such as Rhizobium, which form symbiotic relationships with leguminous plants. Nitrogen fixation is crucial because it makes nitrogen accessible to living organisms, enabling them to synthesize essential biomolecules like amino acids and nucleotides.

Nitrification

Nitrification is a two-step aerobic process in the nitrogen cycle where ammonia is first oxidized to nitrite (NO2-) by bacteria such as Nitrosomonas, and then nitrite is further oxidized to nitrate (NO3-) by bacteria like Nitrobacter. This process is vital for converting ammonia, which can be toxic at high concentrations, into nitrate, a form that plants can readily absorb and utilize for growth.

Denitrification

Denitrification is the microbial process that converts nitrates (NO3-) back into nitrogen gas (N2), effectively returning nitrogen to the atmosphere. This process is carried out by anaerobic bacteria, such as Pseudomonas and Paracoccus, and is essential for maintaining the nitrogen balance in ecosystems. Denitrification helps prevent the accumulation of nitrates in the soil and water, which can lead to environmental issues like eutrophication.