Question

Three carbons of phosphoglyceric acid formed during carbon fixation are derived from

• A. PEP + CO${}_2$
• B. RuBP
• C. CO${}_2$
• D. RuBP + CO${}_2$

Answer 1

Answer: (D)

RuBP + CO${}_2$

Carbon fixation:- A CO2 molecule combines with a five-carbon acceptor molecule, ribulose-1,5-bisphosphate (RuBP). This step makes a six-carbon compound that splits into two molecules of a three-carbon compound, 3-phosphoglyceric acid (3-PGA).

So, the correct option is 'Option D'.