Organisms are mainly composed of C, H, O & N Living organisms also contain S and P as well as several other elements These elements compose the macromolecules.

Organisms are mainly composed of C, H, O & N Living organisms also contain S and P as well as

several other elements These elements compose the macromolecules

carbohydrates, lipids, proteins, and nucleic acids The macromolecules and the elements that

compose them are constantly recycled as they are passed from one organism to the next in a food chain beginning with the autotrophs and ending with decomposers

Cycles of Matter

Cycles of matter that involve biological, geological, and chemical processes

Biological – involves eating, breathing, processing food, and eliminating waste

Geological – volcanic eruptions, formation and breakdown of rock, and major movements within and below the surface of the earth

Chemical – formation of clouds and precipitation, the flow of running water, and lightning

Human activity – mining, burning fossil fuels and wood, clearing land for building or farming, and the manufacture and use of fertilizers affect the cycles of matter on a global scale

Biogeochemical Cycles

The Water Cycle

Water continuously moves between the oceans, atmosphere, and the land – sometimes outside living organisms and sometimes inside them

Transpiration Evaporation Condensation Precipitation Run-Off Water Vapor

The Water Cycle

Macromolecules such as carbohydrates, lipids, proteins, and nucleic acids are NUTRIENTS that organisms need to survive

There are specific element cycles for Carbon, Nitrogen, and Phosphorus

Oxygen and Hydrogen do not have their own cycles as they are combined with other elements in the Water, Carbon, Nitrogen, and Phosphorus cycles

Nutrient Cycles

The Carbon Cycle

Carbon is found in all four macromolecules: Carbohydrates, Lipids, Proteins, and Nucleic Acids

Organic Compounds = Living Compounds◦ Carbon-Based Life◦ Fossil Fuels

Photosynthesis and Cellular Respiration◦ Water + Carbon Dioxide + Sunlight = Oxygen +

Glucose◦ Glucose + Oxygen = Water + Carbon Dioxide + ATP

The Carbon Cycle

The Nitrogen Cycle

Nitrogen is found in the macromolecules Proteins and Nucleic Acids

Nitrogen gas (N2) makes up 78% of the atmosphere◦ This Nitrogen is not in a form usable by organisms◦ Nitrogen Fixation – rhizobacteria and

mycorrhizae Convert nitrogen gas into ammonia (NH3) Other bacteria convert the ammonia to nitrites (NO2

-) and nitrates (NO3

-) that are usable by autotrophs

◦ Denitrification – accomplished by bacteria Convert nitrates into nitrogen gas

The Nitrogen Cycle

The Nitrogen Cycle

N2 (nitrogen fixing bacteria) NH3 or NH4+

Atmospheric nitrogen is converted to ammonia or ammonium ion by nitrogen-fixing bacteria that live in legume root nodules or in soil, or atmospheric nitrogen is converted to nitrogen oxides by lightening.  

NH3 or NH4+ (soil bacteria) NO2

-

NO2- + H2O NO3

- + 2H+

Ammonia and Ammonium are oxidized by soil bacteria first to nitrite ions and then to nitrate ions

NH3 or NO3- or NO2 (denitrifying bacteria) N2

After plants have taken up nitrogen from the soil in the form of nitrate ions, the nitrogen is passed  along the food chain. When those plants and animals dies, bacteria and fungi take up and use some of the nitrogen from the plant/animal protein and other nitrogen containing molecules. The remaining nitrogen is released as ammonium ions or ammonia gas. Denitrifying bacteria convert some ammonia, nitrite, and nitrate back to nitrogen gas, which returns to the atmosphere.

N2 + 3H2 2NH3

Heat + CH4 + H2O 3H2 + CO

CO + H2O H2 + CO2

The Phosphorus Cycle

The phosphorus cycle does not have a significant atmospheric component

Phosphorus remains mostly on land in the form of phosphate rock and soil minerals and in the ocean as dissolved phosphate and phosphate sediment

Phosphorus is not as abundant as C, H, O, N, and S

Phosphorus is found in the macromolecules Lipids, Proteins, and Nucleic Acids

The Phosphorus Cycle