The enzyme RUBisCO has the remarkable property of fixing not only `CO_(2)` but also `O_(2)`. Hence, the name of same enzyme performing the dual role, is RUBP carboxylase oxygenase or RuBisCo.
This enzyme under normal `CO_(2)` conc. Fixes `CO_(2)`. However, when atmospheric conc. of `CO_(2)` is low (i.e., below 1%) and increased concentration of `O_(2)`, this enzyme acts as oxygenase and fixes `O_(2)`.
Ribulose-1,5 bisphosphate `overset(O_(2))to 2` Phosphoglycolic acid + 3 Phosphoglyceric acid.
