what is used by living organisms to produce a number of organic molecules like amino acids, proteins, and nucleic acids.
Ecological Cycles. Nitrogen, Carbon-Oxygen, Phosphorus, Sulfur. The Nitrogen cycle The Nitrogen Cycle Nitrogen is used by living organisms to produce a number of complex organic molecules like amino acids, proteins, and nucleic acids. 78% of the worldâs atmosphere is nitrogen Despite its abundance in the atmosphere, nitrogen is often the most limiting nutrient for plant growth.