nitrogen cycle, definition of

Cyclic movement of nitrogen in different chemical forms from the environment, to organisms, and then back to the environment.

• Secrets Of The Deep Reveal New Information About Nitrogen Cycle
  Scientists have identified an unexpected metabolic ability in a symbiotic community of deep-sea microorganisms. It may help solve a lingering mystery about the world’s nitrogen cycle. The element nitrogen is a critical part of amino acids, the building...

Related Tags: environment, biosphere