In this article we will discuss about the sulphur cycle with the help of diagram. Sulphur, like nitrogen and carbon, is an essential part of all living matter because sulphur containing amino acids are always present in almost all kinds of proteins. Plants can absorb directly the sulphur containing amino acids, e.g., cystine, cysteine, and methionine but these amino acids [...]
Here is an essay on the nitrogen cycle. Nitrogen is one of the important elements in biological compounds, mainly of nucleic acid and protein and, therefore, it is essential for life. Atmosphere contains about 78% nitrogen, but free nitrogen cannot be utilised by most of the organisms, except a few blue green algae and some bacteria. The fixation of nitrogen [...]
Here is an essay on the carbon cycle. Carbon is an essential element that can be cycled from inorganic to organic form. It is present in nature as inorganic CO2 and in living and dead organisms as various organic matters. The cyclic conversion is maintained between inorganic and organic form (Fig. 2.33). CO2 becomes available in nature by microbial decomposition [...]