The Most Ancient CO₂ Fixation Pathway in Anaerobic Phototrophic Bacteria

question 11

Multiple Choice

The most ancient CO₂ fixation pathway in anaerobic phototrophic bacteria and archaea is:

• A) the reverse TCA cycle
• B) the 3-hydroxypropionate cycle
• C) the Calvin cycle
• D) the reductive acetyl-CoA pathway
• E) none of the above

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Definitions:

Rearrangement

A type of chemical reaction in which the structure of a molecule is rearranged to form a new molecule without the removal or addition of elements.

Methanol

A one-carbon alcohol, CH3OH, used as an industrial solvent, antifreeze, fuel, and as a precursor to other chemicals.

Trans-1-Iodo-4-Methylcyclohexane

A chemical compound featuring a cyclohexane ring with iodine and a methyl group attached in a trans configuration, indicating they are on opposite sides of the ring.

Rearrangement

A chemical reaction in which the structure of a molecule is rearranged to form a new molecule.