Q. As compared to a C₃ plant, how many additional molecules of ATP are needed for net production of one molecule of hexose sugar by C₄ plants :
A) 2
B) 6
C) 0
D) 12
Explanation
[Solution from source] A C₃ plant needs 18 ATP per hexose. A C₄ plant also spends 2 ATP per CO₂ to regenerate PEP (pyruvate to PEP), which is 12 more for six CO₂, giving 30 ATP in total. So it needs 12 extra ATP. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.