noun

fixation

The conversion of nitrogen or carbon into compounds organisms can use.

Bacteria in bean roots perform nitrogen fixation, helping plants grow.

Etymology

The Latin root means to fasten. Chemical fixation binds an element into a compound, making it part of a more stable or biologically usable form.

More examples

Carbon fixation allows plants to build sugars from carbon dioxide.
Without nitrogen fixation, many soils would lack enough nitrogen for crops.
Scientists measure carbon fixation in algae under different lighting conditions.

fixation

fix verb — Convert nitrogen or carbon into usable compounds.

assimilation: Emphasizes incorporation into living tissue rather than chemical conversion alone.