By Alyssa May White

Phosphorus Cycle

The most unique element of the Phosphorus Cycle is that, unlike all major cycles, it lacks a gas phase.

In the phosphorus cycle on land, the cycle begins within sedimentary rock. Rain moves the phosphorus from the rocks to the soil, where it is picked up by plants. Animals eat the plants and absorb the phosphorus. Phosphorus is then returned to the soil via the excretion of the animal.

In the aquatic phosphorus cycle, phosphorus begins in runoff. Aquatic life most frequently gains access to phosphorus through erosion. Phosphorus is unable to cling to the water, so it usually settles at the bottom of a body of water. Water plants take in the phosphate and it travels up the aquatic food chain as it does the land food chain.

Phosphorus is also released back into the environment when organisms that have absorbed phosphorus in both the land and aquatic cycles die and decompose.

Big image


Chemical Reactions

The types of chemical reactions involved in the phosphorus cycle include substitution, oxidation, addition, elimination, and oxidative. In a substitution reaction, one group of phosphorus replaces another group of phosphorus. In an oxidation reaction, the amount of oxygen in the phosphorus increases. In an addition reaction, phosphorus combines with another molecule. In an elimination reaction, one molecule becomes two molecules. An oxidative reaction is a combination of an oxidation reaction and an addition reaction.
Big image


Phosphorus Cycle - Learn biology from a real expert

Human Impact

Humans have a negative effect on the phosphorus cycle. Most fertilizers that we use contain phosphorus. Runoff from our farms and gardens bring extra phosphorus into ecosystems that would be better balanced without it. The effect is seen particularly strongly in the aquatic phosphorus cycle. Excess phosphorus causes algae to grow far more rapidly than usual, and the algae uses up all the oxygen, causing areas where nothing else can live.


"Chemical Reactions." The Phosphorus Cycle. N.p., n.d. Web. 18 Nov. 2015.


"The Phosphorus Cycle - Boundless Open Textbook." Boundless. N.p., n.d. Web. 18 Nov. 2015.


"Phosphorus Cycle - The Environmental Literacy Council." The Environmental Literacy Council. N.p., n.d. Web. 18 Nov. 2015.


"Quizlet QWait('dom',function(){document.getElementById('PrintLogo').setAttribute('src',"")});." APES Flashcards. N.p., n.d. Web. 18 Nov. 2015.