rubisco can use ____ or co2 as a substrate
RuBisCO During carbon fixation, the substrate molecules for RuBisCO are ribulose-1,5-bisphosphate and carbon dioxide (distinct from the "activating" carbon dioxide).[11] RuBisCO also catalyses a reaction between ribulose-1,5-bisphosphate and molecular oxygen (O 2) instead of carbon dioxide (CO2).
Light-independent reactions The immediate products of one turn of the Calvin cycle are 2 glyceraldehyde-3-phosphate (G3P) molecules, 3 ADP, and 2 NADP+. (ADP and NADP+ are not really "products." They are regenerated and later used again in the Light-dependent reactions). Each G3P molecule is composed of 3 carbons. For the Calvin cycle to continue, RuBP (ribulose 1,5-bisphosphate) must be regenerated. So, 5 out of 6 carbons from the 2 G3P molecules are used for this purpose. Therefore, there is only 1 net carbon produced to play with for each turn. To create 1 surplus G3P requires 3 carbons, and therefore 3 turns of the Calvin cycle. To make one glucose molecule (which can be created from 2 G3P molecules) would require 6 turns of the Calvin cycle. Surplus G3P can also be used to form other carbohydrates such as starch, sucrose, and cellulose, depending on what the plant needs.[7]