Carbon and Nitrogen Cycles

These flashcards cover key terminology and processes related to the carbon and nitrogen cycles.

Photoautotrophs

Organisms that fix CO2 into organic matter using energy from sunlight.

Chemoheterotrophs

Organisms that use organic matter for energy.

Decomposers

Organisms that oxidize organic compounds from dead plants and animals.

Global warming

The release of CO2 into the atmosphere from burning fossil fuels.

Nitrogen fixation

The bacterial process that converts nitrogen gas (N2) to ammonia (NH3).

Nitrification

The oxidation of ammonium ions to produce nitrite, which is then oxidized to nitrate.

Denitrification

The process where nitrate is used as an electron acceptor by microbes in the absence of oxygen, producing nitrogen gas.

Ammonification

The release of ammonia by bacteria and fungi during the breakdown of organic matter.

Bacteroids

Bacteria that change into modified forms packed in root cells within nodules.

Heterocysts

Specialized cells in cyanobacteria that provide anaerobic conditions for nitrogen fixation.

Rhizobia

Symbiotic nitrogen-fixing bacteria that form root nodules in leguminous plants.

Deamination

The process where amino groups are removed from amino acids and converted to ammonia.