Carbon fixation involves the addition of carbon dioxide to _____.

Carbon fixation involves the addition of carbon dioxide to _____.

1- Rubisco

2- NADPH

3- G3P

4- RuBP

5- 3-PGA

Answer: 4- RuBP

Carbon fixation refers to the ranging of carbon dioxide (CO2) into the organic matter by the living beings. The first step of the Calvin cycle that is the major carbon fixation pathway in plants transforms the molecule of CO2 by an enzyme named RuBisCO which is the abbreviation for Ribulose-1,5-bisphosphate carboxylase/oxygenase that catalyzes the addition of CO2 to the 5-carbon compound called ribulose-1, With the reaction an obvious result is the formation of 2 molecules of 3-phosphoglycerate (3-PGA). Such reaction effectively locks the carbon from CO2 into the organic molecules . RuBP which is the first recipient molecule to CO2 in the carbon fixation cycle, links the acceptance of CO2 to the initiation of the Calvin cycle.