Answer :
Final answer:
Carbon fixation involves the addition of CO2 to ribulose bisphosphate (RuBP), catalyzed by the enzyme RuBisCo, resulting in the production of 3-phosphoglycerate (3-PGA). The correct answer is a) RuBP.
Explanation:
Carbon fixation is a crucial process in the Calvin cycle where an inorganic form of carbon dioxide (CO2) is converted into an organic molecule. This process begins with the enzyme RuBisCo, which catalyzes the reaction between CO2 and a molecule of ribulose bisphosphate (RuBP). For every CO2 molecule that reacts, two molecules of 3-phosphoglycerate (3-PGA) are produced. Thus, answering the original question, carbon fixation involves the addition of carbon dioxide to RuBP, facilitated by the enzyme RuBisCo, leading to the formation of 3-PGA.
During this stage of the Calvin cycle, each turn of the cycle involves the fixation of one CO2 molecule to one RuBP, resulting in two molecules of 3-PGA. The overall number of carbon atoms remains the same as atoms are rearranged to form new bonds. This key step involves 'fixing' the inorganic carbon into a stable organic form that can be utilized by the plant to synthesize glucose and other vital compounds.
Carbon fixation involves the addition of carbon dioxide to RuBP, catalyzed by the enzyme RuBisCO, resulting in the formation of 3-PGA molecules. The correct answer is (a) RuBP.
Carbon fixation involves the addition of carbon dioxide to ribulose bisphosphate (RuBP). This process is catalyzed by the enzyme ribulose bisphosphate carboxylase/oxygenase (RuBisCO). For each CO₂ molecule that reacts with one RuBP, two molecules of 3-phosphoglycerate (3-PGA) are formed. This reaction is the first major step of the Calvin cycle and is crucial for the synthesis of organic molecules in plants.