Question

Sustainability Related Questions:

 1. What is the phosphorus cycle?

 2. What critical role does phosphorus play in the structure of plants?

 3. Why do environmentalist worry about the increasing concentration of phosphates in surface waters?

Answer 1

Answer 1)

The phosphorus cycle is the process by which phosphorus moves through the lithosphere, hydrosphere, and biosphere. Phosphorus is essential for plant and animal growth, as well as the health of microbes inhabiting the soil, but is gradually depleted from the soil over time. The main biological function of phosphorus is that it is required for the formation of nucleotides, which comprise DNA and RNA molecules. Specifically, the DNA double helix is linked by a phosphate ester bond. Calcium phosphate is also the primary component of mammalian bones and teeth, insect exoskeletons, phospholipid membranes of cells, and is used in a variety of other biological functions. The phosphorus cycle is an extremely slow process, as various weather conditions (e.g., rain and erosion) help to wash the phosphorus found in rocks into the soil. In the soil, the organic matter (e.g., plants and fungi) absorb the phosphorus to be used for various biological processes.

Answer 2)

Phosphorus (P) is essential for all living organisms. Plants must have phosphorusfor normal growth and maturity. Phosphorus plays a role in photosynthesis, respiration, energy storage and transfer, cell division, cell enlargement and several other processes in plants.

Answer 3 )

Phosphorus is an essential nutrient for the growth of aquatic vegetation. In many fresh water bodies, P is the most limiting nutrient to the growth of vegetation. Therefore, as P concentration in the water increases, the growth of aquatic vegetation increases. The direct effects of the excessive growth of aquatic vegetation can include a reduction in the transmission of solar radiation and production of toxins . A secondary effect is a decrease in the dissolved oxygen in the water, when bacteria utilize the oxygen while decomposing the increased amounts of dead aquatic vegetation. These effects associated with increased aquatic vegetation growth often have detrimental effects on fish and other aquatic life. This process is a form of eutrophication. In basic terms, eutrophication refers to the excessive growth of aquatic vegetation in surface waters due to nutrient enrichment. In most fresh water bodies, P is the nutrient limiting aquatic vegetation growth.