Carbon cycle

Definition

The carbon cycle is the process through which carbon atoms move between the atmosphere, hydrosphere, lithosphere, and biosphere. It involves various microbial metabolic processes that transform carbon into different chemical forms.

5 Must Know Facts For Your Next Test

1. Microorganisms play a crucial role in the decomposition of organic matter, releasing carbon dioxide back into the atmosphere.
2. Photosynthetic microorganisms such as cyanobacteria convert carbon dioxide into organic compounds using sunlight.
3. Methanogenic archaea produce methane from carbon dioxide and hydrogen in anaerobic conditions.
4. Carbon fixation by chemolithoautotrophic bacteria converts inorganic carbon into organic molecules without sunlight.
5. Syntrophic relationships among microbes can enhance the degradation of complex organic compounds, facilitating the flow of carbon.

Review Questions

• How do photosynthetic microorganisms contribute to the carbon cycle?
• What role do methanogenic archaea play in the carbon cycle?
• Explain how syntrophic relationships among microbes affect the degradation of organic compounds.

Related terms

Carbon Fixation:

The conversion of inorganic carbon (CO2) into organic compounds by living organisms.

Methanogenesis:

A form of anaerobic respiration used by certain archaea where methane is produced as a metabolic byproduct.

Decomposition:

The breakdown of dead organic matter by microorganisms, releasing nutrients back into the environment.