Biogeochemical Cycles: Carbon and Nitrogen

Flashcards covering key vocabulary terms and definitions 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.

Respiration

The process by which energy and CO2 are released, repeating the cycle.

Decomposers

Organisms that oxidize organic compounds from dead plants and animals.

Global warming

The increase in Earth's average temperature, leading to the release of CO2 into the atmosphere from burning fossil fuels.

Nitrogen fixation

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

Nitrogenase

The enzyme used in the process of nitrogen fixation.

Leguminous plants

Plants adapted to form symbiotic relationships with nitrogen-fixing bacteria.

Deamination

The process in which amino groups are removed from amino acids, converting them to ammonia (NH3).

Nitrification

The oxidation of ammonium ions to produce nitrite (NO2-) and then nitrate (NO3-).

Denitrification

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

Rhizobia

Nitrogen-fixing bacteria that attach to the root hairs of leguminous plants and form root nodules.

Ammonification

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

Heterocysts

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