The Phosphorus Cycle

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The Phosphorus Cycle

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  Phosphorus Cycle

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Phosphorus Cycle

• is the biogeochemical cycle that describes the
  movement of phosphorus through the lithosphere,
  hydrosphere, and biosphere. Unlike many other
  biogeochemical cycles, the atmosphere does not
  play a significant role in the movements of
  phosphorus, because phosphorus and
  phosphorus-based compounds are usually solids at
  the typical ranges of temperature and pressure
  found on Earth.
• enters the environment from rocks or deposits
  laid down on the earth many years ago. The
  phosphate rock is commercially available form is
  called apatite. Other deposits may be from
  fossilized bone or bird droppings called guano.
  Weathering and erosion of rocks gradually
  releases phosphorus as phosphate ions which are
  soluble in water. Land plants need phosphate as a
  fertilizer or nutrient.

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The aquatic phosphorus cyclePhosphorus is an
essential nutrient for plants and animals in the
form of ions PO43- and HPO42-. It is a part of
DNA-molecules, of molecules that store energy
(ATP and ADP) and of fats of cell membranes.
Phosphorus is also a building block of certain
parts of the human and animal body, such as the
bones and teeth.
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Phosphorus normally occurs in nature as part of a
phosphate ion, consisting of a phosphorus atom
and some number of oxygen atoms, the most
abundant form (called orthophosphate) having four
oxygens PO4-. Most phosphates are found as salts
in ocean sediments or in rocks. Over time,
geologic processes can bring ocean sediments to
land, and weathering will carry terrestrial .
Plants absorb phosphates from the soil. The
plants may then be consumed by herbivores who in
turn may be consumed by carnivores. After death,
the animal or plant decays, and the phosphates
are returned to the soil. Runoff may carry them
back to the ocean or they may be reincorporated
into rock.
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• The primary biological importance of phosphates
  is as a component of nucleotides, which serve as
  energy storage within cells (ATP) or when linked
  together, form the nucleic acids DNA and RNA.
  Phosphorus is also found in bones, whose strength
  is derived from calcium phosphate, and in
  phospholipids (found in all biological
  membranes).
• Phosphates move quickly through plants and
  animals however, the processes that move them
  through the soil or ocean are very slow, making
  the phosphorus cycle overall one of the slowest
  biogeochemical cycles.

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• Unlike other cycles of matter compounds,
  phosphorus cannot be found in air in the as a
  gas. This is because at normal temperature and
  circumstances, it is a liquid. It usually cycles
  through water, soil and sediments. In the
  atmosphere phosphorus is mainly small dust
  particles.
• Phosphorous is one of the longest cycles, and
  takes a long time to move from sediments to
  living organisms and back to sediments.

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Pictures of Phosphorus Cycle
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Prepared byJUNAL MAY E. TUOZO

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