This article provides a flow diagram of the sulphur cycle. Sulfur is one of the essential elements of life system and its major reservoir lies in the earth's crust together with oceanic sediment. It acts as a component of several compounds like amino acids, protein, enzymes etc. Natural fuel like coal and oils also have some sulfurs (1 to 3%). [...]
This article provides an essay on the phosphorus cycle. Phosphorus is a major constituent of biological membranes, energy rich compounds and nucleic acids. In addition, many animals also need large quantities of this element to make shells, bones and teeth. Since phosphorus does not occur naturally as gas, its cycle, unlike those of carbon and nitrogen, is a sedimentary cycle. [...]
This article provides an essay on the carbon cycle. The carbon cycle is very complex due to the fact that carbon can exist in a wide variety of different types of compounds, occupying in plants, animals, rocks, liquid, sediments and air. The most important carbonaceous materials are CO2, CO, carbonates, and organic carbonaceous materials. In the atmosphere 0.03 per cent [...]