Nitrogen being 79 per cent of the atmosphere, the atmospheric phase is predominant in the global nitrogen cycle. It is required by organisms in the synthesis of proteins, nucleic acids, and other nitrogenous compounds. Atmospheric nitrogen serves as the ultimate source. But aerial nitrogen, the most abundant component of air, is rather inert chemically and actually cannot be used as [...]
The atmosphere contains about 21% oxygen. The atmospheric oxygen enters the living organisms, as a gas required in respiration. During this process carbon dioxide and water are formed. C6 H12 O6 + 6O2 -----> 6 CO2 + 6 H2O + energy The metabolic water thus formed is added to all other water present in living organisms and as such it [...]
The Phosphorus cycle, unlike those of Carbon and Nitrogen cycles lacks an atmospheric component. The global phosphorus cycle involves only aquatic and soil compartments. As a basic constituent of nucleic acids, phospholipids and numerous phosphorylated compounds, phosphorus is one of the nutrients of major importance to biological systems. Further, as Hutchinson has noted, because the ratio of phosphorus to other [...]