Calvin-Benson-Bassham reductive pentose-phosphate cycle

Carbon fixation by the Calvin-Benson-Bassham reductive pentose-phosphate cycle, as a taxon-neutral decomposition: Rubisco carboxylation of ribulose 1,5-bisphosphate, reduction of 3-phosphoglycerate to triose phosphate, and regeneration of the acceptor. Two regulatory parts travel with the cycle because they act on its own enzymes: Rubisco activase, which removes inhibitory sugar phosphates from Rubisco active sites, and the CP12 redox scaffold, which assembles an autoinhibitory PRK-GAPDH complex in the dark and releases it on thioredoxin/NTRC reduction. The cycle consumes the ATP and NADPH produced by MODULE:thylakoid_light_reactions, and is the Rubisco compartment that carbon-concentrating mechanisms feed, including the algal MODULE:pyrenoid_ccm. It is not restricted to oxygenic phototrophs: the same cycle fixes carbon in anoxygenic phototrophs and in chemoautotrophs, which is why it is modelled separately from photosynthesis. The non-CBB fixation routes are siblings rather than parts: MODULE:reductive_tca_cycle, MODULE:wood_ljungdahl_pathway and MODULE:hydroxypropionate_bicycle. The carbon-concentrating mechanisms that raise CO2 at this cycle's Rubisco are also siblings: MODULE:c4_carbon_shuttle and MODULE:cam_carbon_shuttle each include this module by reference, while MODULE:pyrenoid_ccm does not - it models Rubisco carboxylation inline and carries no module_ref - so it feeds this cycle in biology without composing it in the model. Converting it is a separate change against that module.

Extracted from MODULE:oxygenic_photosynthesis, which now includes this module by reference, so that each module stays small enough to read and can be reused on its own. Identifiers are grounded only where verified against the local GO term cache, GOlr, or UniProt; descriptors without a `term` are deliberate (no confident identifier yet) rather than oversights. Representative UniProt members are concrete orienting examples, not exhaustive or species-restricting claims.