Why is RuBisCo more appropriately called RUBP carboxylase - oxygenase and what important role does it play in photosynthesis.

RuBisCo is appropriately called RUBP carboxylase - oxygenase because the enzyme catalyses the carboxylation (the chemical process by which a carboxyl group -COOH is added) of ribulose-1,5-bisphosphate, RuBP, a 5-carbon  compound, by carbon dioxide (a total of 6 carbons) in a two-step reaction. Sometimes the magnesium metal center of Rubisco coordinates to RuBP and oxygen instead of carbon dioxide.  Rubisco then catalyzes an oxygenase reaction. Under normal conditions the rate of the carboxylase reaction is 4 times faster than the oxygenase reaction.

Role of Rubisco is the enzyme that attaches each carbon dioxide molecule to a molecule of ribulose biphosphate. It provides acceptor molecules that consume the products of the light reactions of photosynthesis, and regulates the pool sizes of important photosynthetic intermediates. 


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