Nitrogen, Carbon, Phosphorus Cycles

Nitrogen Fixation

Converting atmospheric nitrogen (N₂) into ammonia (NH₃) or related compounds, primarily by nitrogen-fixing bacteria.

Nitrification

A two-step process where ammonia (NH₃) is converted to nitrites (NO₂⁻) and then to nitrates (NO₃⁻) by nitrifying bacteria.

Assimilation

The uptake of nitrates and ammonia by plants and animals to synthesize proteins and nucleic acids.

Ammonification

The conversion of organic nitrogen (from dead organisms and waste) back into ammonia (NH₃) by decomposers.

Denitrification

The process of converting nitrates (NO₃⁻) back into atmospheric nitrogen (N₂) by denitrifying bacteria.

Weathering

The breakdown of rocks containing phosphorus into soil and water, making phosphorus available for plant uptake.

Uptake by Plants

The absorption of phosphate ions (PO₄³⁻) from the soil by plant roots, essential for energy transfer and genetic processes.

Consumption by Animals

The process by which animals obtain phosphorus by consuming plants or other animals.

Decomposition

The breakdown of organic matter by decomposers, releasing nutrients (including phosphorus) back into the soil.

Sedimentation

The process where phosphorus is washed into bodies of water, where it can precipitate and form sedimentary rocks.

Phosphate Ions (PO₄³⁻)

The inorganic form of phosphorus that plants absorb from the soil.

Biological Molecules

Molecules essential for life, including proteins, nucleic acids, and ATP, which require nitrogen and phosphorus for their formation.

Carbon Cycle

The series of processes through which carbon atoms circulate through the atmosphere, land, and living organisms.

Photosynthesis

The process by which plants convert carbon dioxide (CO₂) and sunlight into glucose (C₆H₁₂O₆) and oxygen (O₂).

Respiration

The process by which living organisms convert glucose (C₆H₁₂O₆) and oxygen (O₂) back into carbon dioxide (CO₂) and energy.

Decomposition

The breakdown of dead organic matter by decomposers, releasing carbon back into the soil and atmosphere.

Carbon Reservoirs

Locations where carbon is stored, including the atmosphere, oceans, soil, biomass, and fossil fuels.

Carbon Flux

The movement of carbon between different reservoirs through processes like photosynthesis, respiration, and decomposition.

Combustion

The process of burning fossil fuels or biomass, which releases carbon dioxide (CO₂) into the atmosphere.

Carbon Sequestration

The long-term storage of carbon in natural sinks, such as forests, oceans, and soil, to reduce atmospheric CO₂ levels.

Autotrophs

Organisms, such as plants, that produce their own food through photosynthesis and play a key role in the carbon cycle.

Short Carbon Cycle

The rapid cycling of carbon through photosynthesis and respiration, typically occurring on a seasonal basis.

Long Carbon Cycle

The geological processes that store carbon for millions of years, such as sedimentation and fossilization.

Greenhouse Effect

The warming of the Earth's atmosphere due to the trapping of heat by greenhouse gases, including carbon dioxide (CO₂).

Global Warming

The long-term increase in Earth's average surface temperature due to human activities, primarily through the release of greenhouse gases.

Order of Nitrogen Cycle Process?

Nitrogen Fixation
Nitrification
Assimilation
Ammonification
Denitrification

Order of Phosphorus Cycle Process?

Weathering
Uptake by Plants
Consumption by Animals
Decomposition
Sedimentation

Order of Carbon Cycle Process?

Photosynthesis
Respiration
Decomposition
Combustion

Carbon Reservoirs Examples + Explanation

Atmosphere: Carbon dioxide (CO₂) and methane (CH₄) are stored in the air.
Biosphere: Carbon is found in living organisms (plants, animals, and microbes).
Soil: Organic carbon in the form of decomposed matter and soil organic matter.
Oceans: Dissolved CO₂ and organic carbon in marine organisms.
Fossil Fuels: Coal, oil, and natural gas, which are long-term carbon storage.

Nitrogen Reservoirs Examples + Explanation

Atmosphere: Approximately 78% nitrogen gas (N₂).
Soil: Nitrates (NO₃⁻), nitrites (NO₂⁻), ammonia (NH₃), and organic nitrogen compounds.
Biosphere: Nitrogen found in living organisms (proteins, nucleic acids).
Water Bodies: Dissolved forms of nitrogen (e.g., nitrates) in rivers and lakes.

Phosphorus Reservoirs Examples + Explanation

Lithosphere: Phosphorus is found in rocks and minerals (mostly as phosphate ions, PO₄³⁻).
Soil: Available phosphate ions in soil and organic matter.
Biosphere: Phosphorus in living organisms (nucleic acids, ATP, and phospholipids).
Water Bodies: Dissolved phosphorus in rivers, lakes, and oceans.