Reverse Krebs cycle

The reaction is basically the Citric acid cycle run in reverse. Where the Krebs cycle takes complex carbon molecules in the form of sugars and oxidizes them to CO₂ and water, the reverse cycle takes CO₂ and water to make carbon compounds. This process is used by some bacteria to synthesise carbon compounds, sometimes using hydrogen or sulphates as electron donors. In this process it can be seen as an alternative to the far more common photosynthesis production of organic molecules.

The reaction is one of the possible candidates for prebiotic early earth conditions and so is of interest in the origin of life research. It has been found that some of the steps can be catalysed by minerals.

See also

• Carbon fixation

References