Carbon fixation

Definition

Carbon fixation is the process by which inorganic carbon (typically carbon dioxide) is converted into organic compounds by living organisms. This process is essential for the production of energy and biomass in autotrophic organisms such as plants, algae, and certain bacteria.

5 Must Know Facts For Your Next Test

1. The Calvin cycle is the primary pathway for carbon fixation in photosynthetic organisms.
2. Rubisco is a critical enzyme that catalyzes the first step of carbon fixation in the Calvin cycle.
3. Certain prokaryotes, such as cyanobacteria, are capable of carbon fixation through photosynthesis.
4. Carbon fixation can also occur via chemosynthesis in some bacteria, using chemical energy from inorganic molecules rather than light.
5. Carbon fixation contributes to the global carbon cycle, influencing atmospheric CO2 levels and climate change.

Review Questions

• What is the role of Rubisco in carbon fixation?
• How do cyanobacteria contribute to carbon fixation?
• Describe one way that carbon fixation impacts the global carbon cycle.

Related terms

Calvin Cycle:

A series of biochemical reactions that take place in the chloroplasts of photosynthetic organisms during which carbon dioxide is converted into glucose.

Chemosynthesis:

The process by which some microorganisms create organic compounds using chemical energy derived from reactions involving inorganic molecules.

Rubisco: An enzyme involved in the first major step of carbon fixation in the Calvin cycle.